hello, could you go to firefox > 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...

Reset Firefox to its default state

If you're having major problems which you can't resolve, start fresh with only your essential information. Troubleshooting Information This page contains technical information that might be useful when you're trying to solve a problem. If you are looking for answers to common questions about Firefox, check out our support website. Application Basics Name Firefox Version 28.0 Update History User Agent Mozilla/5.0 (Windows NT 5.1; rv:28.0) Gecko/20100101 Firefox/28.0 Profile Folder Enabled Plugins about:plugins Build Configuration about:buildconfig Memory Use about:memory Crash Reports for the Last 3 Days Report ID Submitted

All Crash Reports (including 1 pending crash in the given time range) Extensions Name Version Enabled ID IE Tab 2 (FF 3.6+) 5.12.12.1 true {1BC9BA34-1EED-42ca-A505-6D2F1A935BBB} Important Modified Preferences Name Value browser.cache.disk.capacity 358400 browser.cache.disk.smart_size.first_run false browser.cache.disk.smart_size.use_old_max false browser.cache.disk.smart_size_cached_value 358400 browser.places.smartBookmarksVersion 6 browser.sessionstore.upgradeBackup.latestBuildID 20140314220517 browser.startup.homepage_override.buildID 20140314220517 browser.startup.homepage_override.mstone 28.0 browser.tabs.warnOnClose false dom.ipc.plugins.enabled.npietab2.dll true dom.mozApps.used true extensions.lastAppVersion 28.0 gfx.blacklist.direct2d 3 gfx.blacklist.layers.direct3d10 3 gfx.blacklist.layers.direct3d10-1 3 gfx.blacklist.layers.direct3d9 3 gfx.blacklist.layers.opengl 3 gfx.blacklist.stagefright 3 gfx.blacklist.suggested-driver-version 6.1400.1000.5218 gfx.blacklist.webgl.angle 3 gfx.blacklist.webgl.msaa 3 gfx.blacklist.webgl.opengl 3 network.cookie.prefsMigrated true places.database.lastMaintenance 1396781495 places.history.expiration.transient_current_max_pages 51821 plugin.disable_full_page_plugin_for_types application/pdf plugin.importedState true plugin.state.java 0 privacy.sanitize.migrateFx3Prefs true storage.vacuum.last.index 1 storage.vacuum.last.places.sqlite 1394804869 Graphics Adapter Description Mobile Intel(R) 4 Series Express Chipset Family Adapter Drivers igxprd32 Adapter RAM Unknown Device ID 0x2a42 Direct2D Enabled Blocked for your graphics driver version. Try updating your graphics driver to version 6.1400.1000.5218 or newer. DirectWrite Enabled false (0.0.0.0) Driver Date 10-19-2009 Driver Version 6.14.10.5160 GPU #2 Active false GPU Accelerated Windows 0/1 Basic Blocked for your graphics driver version. Try updating your graphics driver to version 6.1400.1000.5218 or newer. Vendor ID 0x8086 WebGL Renderer Blocked for your graphics driver version. Try updating your graphics driver to version 6.1400.1000.5218 or newer. windowLayerManagerRemote false AzureCanvasBackend skia AzureContentBackend cairo AzureFallbackCanvasBackend cairo AzureSkiaAccelerated 0 JavaScript Incremental GC true Accessibility Activated false Prevent Accessibility 0 Library Versions Expected minimum version Version in use NSPR 4.10.3 4.10.3 NSS 3.15.5 Basic ECC 3.15.5 Basic ECC NSSSMIME 3.15.5 Basic ECC 3.15.5 Basic ECC NSSSSL 3.15.5 Basic ECC 3.15.5 Basic ECC NSSUTIL 3.15.5 3.15.5

thanks you - there's nothing that looks particularly suspicious in there. just to be sure, can you also try if the same thing is happening when you launch firefox in safe mode once?

Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

otherwise please run a full scan of your system with the security software already in place and different other tools like the free version of malwarebytes and adwcleaner to see if they catch anything suspicious running on your system...

Troubleshoot Firefox issues caused by malware

Ok, thanks. i will scan to see if anything is picked up.

Maybe it has something to do with this:

• http://joomla4ever.ru/en/extensions-shape5/966-s5-reservations.html

Yes, that's what i found searching the web. I fixed it with a malware scan..it doesn't appear anymore. Thanks.