Hello Victor.

You may be having a problem with some Firefox add-on that is hindering your Firefox's normal behavior. Have you tried disabling all add-ons (just to check), to see if Firefox goes back to normal?

Whenever you have a problem with Firefox, whatever it is, you should make sure it's not coming from one of your installed add-ons, be it an extension, a theme or a plugin. To do that easily and cleanly, run Firefox in safe mode and select Disable all add-ons. If the problem disappears, you know it's from an add-on. Disable them all in normal mode, and enable them one at a time until you find the source of the problem. See this article for information about troubleshooting extensions and theme. You can troubleshoot plugins the same way.

If you want support for one of your add-ons, you'll need to contact its author.

Tried running in safe mode and disabling all add-ons. It made no difference, the same problem continues

That is weird. Please try creating a new (temporary) Firefox profile: http://support.mozilla.com/en-US/kb/Managing+profiles Tell me if the new profile has the same issue.

Thanks. The new temporary profile does not have that issue. Now what do I do next?

I set up the temporary user profile as you suggested. Now everything works fine within the temporary user profile. I am able to create new bookmarks by dragging URLs either to the bookmark menu or the bookmark toolbar. I am also able to open and edit existing bookmark properties (rename them, change their URLs, etc.).

What do I do next to get all my original profile's saved bookmarks, preferences, saved passwords, etc. to work in the new profile. Or do I do something else to my original profile to get those features to work once again? Once I get all this stuff into the temporary profile (I'll need an explanation on how to do that) do I rename the temporary profile and delete my original profile? Or what?

Victor, that was mostly for diagnostic purposes. It means your own profile has a problem that is causing this issue. Which is good because we know it's a problem with the profile and not with something outside Firefox. Please, on your own profile, run Firefox in safe mode to reset its settings to default (there's a box you need to tick, when you run it in safe mode). See if that makes the issue disappear in safe mode.

There's also a possibly easier route which is to transport your settings, bookmarks, add-ons and so on, from your old profile into the new one. I understand if you don't want to do that, of course, and hopefully I'll be able to help you fix the issue with your profile.

See http://kb.mozillazine.org/Locked_or_damaged_places.sqlite

I tried cor-el's recommendation and tried to backup and restore my bookmarks as mentioned in the "Locked or damaged places.sqlite" article as my problem only relates to bookmarks. However when I tried to restore the bookmark backup I made I received a message that it was "unable to process the backup file." I then tried to restore all the bookmark backups Firefox had made (going back to June 22) but received the same message bookmark restore attempt.

I just tried Morbus' recommendation and ran my own profile in safe mode, reset settings to default, and restarted Firefox. This had no impact on the original problem. Morbus also recommended transporting my settings, bookmarks, add-ons and so on from my original profile to my new one. How do I do this? Will doing this also transfer my saved passwords?

In addition to the existing problem of not being able to drag URLs to create bookmarks, or edit existing bookmark properties I have a new bookmark problem.

When I opened Firefox today about half my bookmarks and bookmark folders have disappeared. I have tried restoring all saved bookmark backups but at each attempt I received the message "unable to process the backup file."

I could really use some help in getting Firefox to work properly. I would rather not start from scratch by uninstalling and reinstalling Firefox. I especially want to retain my saved passwords.

Any advice?