Hi crabpaws,
create a New Profile as a test to check if your current profile is causing the problems. These articles may help you:

• Profiles - Where Firefox stores your bookmarks, passwords and other user data
• Profile Manager - Create, remove or switch Firefox profiles

If the new profile works then you can recover your Bookmarks and Passwords from the old profile:

• Recovering important data from an old profile

Did this help you?

You may have installed an extension like TACO (Abine) or Do Not Track Plus that maintains a set of OPT-OUT cookies if you can't remove some cookies permanently.

• http://en.wikipedia.org/wiki/HTTP_cookie
• http://en.wikipedia.org/wiki/Do_Not_Track

In that case you need to uninstall the extension to remove those opt-out cookies.

• Do Not Track Plus: https://addons.mozilla.org/firefox/addon/donottrackplus/

Thanks for the suggestion. I've got DoNotTrackMe installed, BUT deleting cookies has been working with DoNotTrackMe installed -- until recently.

You should be able to delete regular cookies, only the opt-out cookies added by the extension are permanent and can't be deleted.

No, I cannot delete regular cookies.

If clearing cookies doesn't work then it is possible that the cookies.sqlite file that stores the cookies is corrupted.

Rename (or delete) cookies.sqlite (cookies.sqlite.old) and delete other present cookie files like cookies.sqlite-journal in the Firefox Profile Folder in case the file cookies.sqlite got corrupted.

• http://kb.mozillazine.org/Cookies
• https://support.mozilla.org/kb/Deleting+cookies

Did you try to disable all extensions to see if that helps?

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

See my initial post. I followed the instructions here a couple of times https://support.mozilla.org/en-US/questions/919470