Here are the general things:

When you have a problem with one particular site, a good "first thing to try" is clearing your Firefox cache and deleting your saved cookies for the site.

(1) Clear Firefox's Cache

"3-bar" menu button (or Tools menu) > Options > Advanced

On the Network mini-tab > Cached Web Content : "Clear Now"

If you have a large hard drive, this might take a few minutes.

(2) Remove the site's cookies. Try starting directly on https://disqus.com/ and then use either:

• right-click and choose View Page Info > Security > "View Cookies"
• (menu bar) Tools > Page Info > Security > "View Cookies"
• click the padlock or globe icon in the address bar > More Information > "View Cookies"

In the dialog that opens, disqus.com should be pre-entered in the box at the top to filter your cookie list, and you can remove the site's cookies individually.

Then try reloading a page that uses Disqus. Does that help?

Could you test in Firefox's Safe Mode? That's a standard diagnostic tool to deactivate extensions and some advanced features of Firefox. More info: Diagnose Firefox issues using Troubleshoot Mode.

If Firefox is not running: Hold down the Shift key when starting Firefox.

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" button > Restart with Add-ons Disabled
• Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement?

Since you have Privacy Badger, which sets site-specific cookie policies (allow/block), it might be difficult to get a clean test in your existing profile. Do you want to try the new profile test again? I wouldn't use a command window. Instead:

Using Start menu > search box (or the Run dialog, Windows key + r) and type or paste and then press Enter:

firefox.exe -P

That should display the profile manager dialog -- don't delete anything here!

Any time you want to switch profiles, exit Firefox and return to this dialog.

Click the Create Profile button, assign a name like TEST062615, and skip the option to relocate the profile folder. After creating the profile, select it and start Firefox in that profile.

Any difference on the affected sites?

When returning to the Profile Manager, you might be tempted to use the Delete Profile button. But... it's a bit too easy to accidentally delete your "real" profile, so I recommend resisting the temptation. If you do want to clean up later, I suggest making a backup of all your profiles first in case something were to go wrong.

I used the Windows + r key and the Run box opened. I typed in firefox.exe -P, putting a space between the exe and the P and making it a capital P. I hit enter and the browser opened up. I did not see any box I thought to be the profile manager dialog. What am I doing incorrectly. I'm using Windows 7 and Firefox v. 38.0.5. Thank you, Mike Butler

You can only open the Profile Manager if Firefox isn't still running, so you can check that in the Windows Task Manager on the Processes tab.

You can remove all data stored in Firefox from a specific domain via "Forget About This Site" in the right-click context menu of an history entry ("History > Show All History" or "View > Sidebar > History") or via the about:permissions page.

Using "Forget About This Site" will remove all data stored in Firefox from that domain like bookmarks, cookies, passwords, cache, history, and exceptions, so be cautious and if you have a password or other data from that domain that you do not want to lose then make sure to backup this data or make a note.

You can't recover from this 'forget' unless you have a backup of the involved files.

It doesn't have any lasting effect, so if you revisit such a 'forgotten' website then data from that website will be saved once again.

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem.

• Switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance
• Do NOT click the Reset button on the Safe Mode start window

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes