hi jamesthompson, could you go to the firefox menu ≡ > help ? > troubleshooting information, copy the contents of that page and paste them here into a reply on the forum? this might give us a clue what is going on...

Name: Firefox Version: 40.0 Build ID: 20150807085045 Update Channel: release User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:40.0) Gecko/20100101 Firefox/40.0 Multiprocess Windows: 0/2 (default: false)

Crash Reports for the Last 3 Days

All Crash Reports (including 1 pending crash in the given time range)

Extensions

Name: Amazon Price Tracker - Keepa.com Version: 1.75 Enabled: true ID: amptra@keepa.com

Name: Dashlane Version: 3.5.0.89717 Enabled: true ID: {442718d9-475e-452a-b3e1-fb1ee16b8e9f}

Name: Logitech SetPoint Version: 6.5 Enabled: true ID: {F003DA68-8256-4b37-A6C4-350FA04494DF}

Name: McAfee SafeKey Version: 2.2.3 Enabled: true ID: {072844D3-7DEE-45F6-A406-E87F76302E4B}

Name: McAfee WebAdvisor Version: 4.0.0 Enabled: true ID: {4ED1F68A-5463-4931-9384-8FFF5ED91D92}

Name: SmartPrintButton Version: 1.0 Enabled: false ID: quickprint@hp.com

Graphics

Adapter Description: Intel(R) HD Graphics Family Adapter Drivers: igdumd64 igd10umd64 igd10umd64 igdumdx32 igd10umd32 igd10umd32 Adapter RAM: Unknown Asynchronous Pan/Zoom: none Device ID: 0x0116 Direct2D Enabled: true DirectWrite Enabled: true (6.2.9200.17461) Driver Date: 3-25-2011 Driver Version: 8.15.10.2342 GPU #2 Active: false GPU Accelerated Windows: 2/2 Direct3D 11 (OMTC) Subsys ID: 397517aa Supports Hardware H264 Decoding: true Vendor ID: 0x8086 WebGL Renderer: Google Inc. -- ANGLE (Intel(R) HD Graphics Family Direct3D9Ex vs_3_0 ps_3_0) windowLayerManagerRemote: true AzureCanvasBackend: direct2d 1.1 AzureContentBackend: direct2d 1.1 AzureFallbackCanvasBackend: cairo AzureSkiaAccelerated: 0 (#0) Error: OpenSharedResource failed for format 65 (#1) Error: [D2D1.1] Attempt to use unsupported surface size Size(1191,9020) (#2) Error: Failed to create DrawTarget, Type: 7 Size: Size(1191,9020) (#3) Error: [D2D1.1] Attempt to use unsupported surface size Size(1191,10658) (#4) Error: Failed to create DrawTarget, Type: 7 Size: Size(1191,10658)

Important Modified Preferences

browser.cache.disk.capacity: 358400 browser.cache.disk.filesystem_reported: 1 browser.cache.disk.smart_size_cached_value: 358400 browser.cache.disk.smart_size.first_run: false browser.cache.disk.smart_size.use_old_max: false browser.cache.frecency_experiment: 1 browser.download.importedFromSqlite: true browser.link.open_newwindow: 2 browser.places.smartBookmarksVersion: 7 browser.search.suggest.enabled: false browser.sessionstore.upgradeBackup.latestBuildID: 20150807085045 browser.startup.homepage: http://www.amazon.com/ browser.startup.homepage_override.buildID: 20150807085045 browser.startup.homepage_override.mstone: 40.0 browser.tabs.drawInTitlebar: false browser.tabs.loadInBackground: false browser.tabs.onTop: false browser.tabs.warnOnOpen: false browser.urlbar.autoFill: false dom.apps.reset-permissions: true dom.disable_open_during_load: false dom.mozApps.used: true dom.w3c_touch_events.expose: false extensions.lastAppVersion: 40.0 font.internaluseonly.changed: false general.autoScroll: false gfx.direct3d.last_used_feature_level_idx: 0 gfx.direct3d.prefer_10_1: true keyword.URL: https://search.yahoo.com/search?fr=mcafee&type=B111US714D20140725&p= media.gmp-eme-adobe.lastUpdate: 1437786673 media.gmp-eme-adobe.version: 12 media.gmp-gmpopenh264.lastUpdate: 1431876213 media.gmp-gmpopenh264.version: 1.4 media.gmp-manager.buildID: 20150807085045 media.gmp-manager.lastCheck: 1439459606 network.cookie.prefsMigrated: true network.predictor.cleaned-up: true places.database.lastMaintenance: 1439210169 places.history.expiration.transient_current_max_pages: 104858 plugin.disable_full_page_plugin_for_types: application/pdf plugin.importedState: true plugin.state.npctrl: 1 print.printer_Brother_HL-2170W_series_Printer.print_bgcolor: false print.printer_Brother_HL-2170W_series_Printer.print_bgimages: false print.printer_Brother_HL-2170W_series_Printer.print_colorspace: am Files (x86) print.printer_Brother_HL-2170W_series_Printer.print_command: Files (x86) print.printer_Brother_HL-2170W_series_Printer.print_downloadfonts: false print.printer_Brother_HL-2170W_series_Printer.print_duplex: 5505107 print.printer_Brother_HL-2170W_series_Printer.print_edge_bottom: 0 print.printer_Brother_HL-2170W_series_Printer.print_edge_left: 0 print.printer_Brother_HL-2170W_series_Printer.print_edge_right: 0 print.printer_Brother_HL-2170W_series_Printer.print_edge_top: 0 print.printer_Brother_HL-2170W_series_Printer.print_evenpages: true print.printer_Brother_HL-2170W_series_Printer.print_footercenter: iles (x86) print.printer_Brother_HL-2170W_series_Printer.print_footerleft: &PT print.printer_Brother_HL-2170W_series_Printer.print_footerright: &D print.printer_Brother_HL-2170W_series_Printer.print_headercenter: es (x86) print.printer_Brother_HL-2170W_series_Printer.print_headerleft: &T print.printer_Brother_HL-2170W_series_Printer.print_headerright: &U print.printer_Brother_HL-2170W_series_Printer.print_in_color: true print.printer_Brother_HL-2170W_series_Printer.print_margin_bottom: 0.5 print.printer_Brother_HL-2170W_series_Printer.print_margin_left: 0.5 print.printer_Brother_HL-2170W_series_Printer.print_margin_right: 0.5 print.printer_Brother_HL-2170W_series_Printer.print_margin_top: 0.5 print.printer_Brother_HL-2170W_series_Printer.print_oddpages: true print.printer_Brother_HL-2170W_series_Printer.print_orientation: 0 print.printer_Brother_HL-2170W_series_Printer.print_page_delay: 50 print.printer_Brother_HL-2170W_series_Printer.print_paper_data: 1 print.printer_Brother_HL-2170W_series_Printer.print_paper_height: 11.00 print.printer_Brother_HL-2170W_series_Printer.print_paper_name: (x86) print.printer_Brother_HL-2170W_series_Printer.print_paper_size_type: 0 print.printer_Brother_HL-2170W_series_Printer.print_paper_size_unit: 0 print.printer_Brother_HL-2170W_series_Printer.print_paper_width: 8.50 print.printer_Brother_HL-2170W_series_Printer.print_plex_name: x86) print.printer_Brother_HL-2170W_series_Printer.print_resolution: 3997797 print.printer_Brother_HL-2170W_series_Printer.print_resolution_name: 6) print.printer_Brother_HL-2170W_series_Printer.print_reversed: false print.printer_Brother_HL-2170W_series_Printer.print_scaling: 1.00 print.printer_Brother_HL-2170W_series_Printer.print_shrink_to_fit: false print.printer_Brother_HL-2170W_series_Printer.print_to_file: false print.printer_Brother_HL-2170W_series_Printer.print_unwriteable_margin_bottom: 0 print.printer_Brother_HL-2170W_series_Printer.print_unwriteable_margin_left: 0 print.printer_Brother_HL-2170W_series_Printer.print_unwriteable_margin_right: 0 print.printer_Brother_HL-2170W_series_Printer.print_unwriteable_margin_top: 0 print.printer_Brother_HL-L2340D_series.print_bgcolor: false print.printer_Brother_HL-L2340D_series.print_bgimages: false print.printer_Brother_HL-L2340D_series.print_colorspace: am Files (x86) print.printer_Brother_HL-L2340D_series.print_command: Files (x86) print.printer_Brother_HL-L2340D_series.print_downloadfonts: false print.printer_Brother_HL-L2340D_series.print_duplex: 5505107 print.printer_Brother_HL-L2340D_series.print_edge_bottom: 0 print.printer_Brother_HL-L2340D_series.print_edge_left: 0 print.printer_Brother_HL-L2340D_series.print_edge_right: 0 print.printer_Brother_HL-L2340D_series.print_edge_top: 0 print.printer_Brother_HL-L2340D_series.print_evenpages: true print.printer_Brother_HL-L2340D_series.print_footercenter: iles (x86) print.printer_Brother_HL-L2340D_series.print_footerleft: &PT print.printer_Brother_HL-L2340D_series.print_footerright: &D print.printer_Brother_HL-L2340D_series.print_headercenter: es (x86) print.printer_Brother_HL-L2340D_series.print_headerleft: &T print.printer_Brother_HL-L2340D_series.print_headerright: print.printer_Brother_HL-L2340D_series.print_in_color: true print.printer_Brother_HL-L2340D_series.print_margin_bottom: 0.5 print.printer_Brother_HL-L2340D_series.print_margin_left: 0.5 print.printer_Brother_HL-L2340D_series.print_margin_right: 0.5 print.printer_Brother_HL-L2340D_series.print_margin_top: 0.5 print.printer_Brother_HL-L2340D_series.print_oddpages: true print.printer_Brother_HL-L2340D_series.print_orientation: 0 print.printer_Brother_HL-L2340D_series.print_page_delay: 50 print.printer_Brother_HL-L2340D_series.print_paper_data: 1 print.printer_Brother_HL-L2340D_series.print_paper_height: 11.00 print.printer_Brother_HL-L2340D_series.print_paper_name: (x86) print.printer_Brother_HL-L2340D_series.print_paper_size_type: 0 print.printer_Brother_HL-L2340D_series.print_paper_size_unit: 0 print.printer_Brother_HL-L2340D_series.print_paper_width: 8.50 print.printer_Brother_HL-L2340D_series.print_plex_name: x86) print.printer_Brother_HL-L2340D_series.print_resolution: 3997797 print.printer_Brother_HL-L2340D_series.print_resolution_name: 6) print.printer_Brother_HL-L2340D_series.print_reversed: false print.printer_Brother_HL-L2340D_series.print_scaling: 1.00 print.printer_Brother_HL-L2340D_series.print_shrink_to_fit: true print.printer_Brother_HL-L2340D_series.print_to_file: false print.printer_Brother_HL-L2340D_series.print_unwriteable_margin_bottom: 0 print.printer_Brother_HL-L2340D_series.print_unwriteable_margin_left: 0 print.printer_Brother_HL-L2340D_series.print_unwriteable_margin_right: 0 print.printer_Brother_HL-L2340D_series.print_unwriteable_margin_top: 0 print.printer_EPSON16FEE9_(Epson_Stylus_NX430).print_bgcolor: false print.printer_EPSON16FEE9_(Epson_Stylus_NX430).print_bgimages: false print.printer_EPSON16FEE9_(Epson_Stylus_NX430).print_colorspace: rogram Files (x86) print.printer_EPSON16FEE9_(Epson_Stylus_NX430).print_command: gram Files (x86) print.printer_EPSON16FEE9_(Epson_Stylus_NX430).print_downloadfonts: false print.printer_EPSON16FEE9_(Epson_Stylus_NX430).print_duplex

thank you - that's likely an issue with hardware acceleration. please try updating your graphics driver (this should be the right link for your configuration): https://downloadcenter.intel.com/download/24971/Intel-HD-Graphics-Driver-for-Windows-7-8-64-bit

or in case this doesn't solve the issue or there is no new version available at the moment, disable hardware acceleration in the firefox menu ≡ > options > advanced > general (that setting will take a restart of the browser to take effect).

Thanks. For now, I have disabled hardware acceleration and the problem is gone.

Would you advise reenabling it and downloading the link you suggested. Would this enhance performance?

yes exactly, that's why i'd go for a driver update first and only disable hwa if there are no other options. could you report back once you have tried the update? thanks...