When I "copy" text from a website and "paste" it in an email or Word document, the receiving application locks up.
I first noticed this problem yesterday when trying to copy/paste into Word 2003. I disabled all Add-ons, restarted FF, problem solved. I enabled all Add-ons, restarted FF and problem went away. Today it is back but not only a problem with Word but Windows Live Mail too. I see others have this problem so it seems to be a FF problem and not just mine. I'm running FF 15.0.1.
That's what I changed, the Location Bar section. Under History, I've selected "Use custom settings" and it has been set that way for a long time.
It may be time to try a reset. Make a note of your current extensions. If any of them stores data locally in your Firefox settings, we should investigate whether/how you can migrate that data.
Firefox's Reset feature, as noted much earlier in this thread, duplicates certain key data from your active settings folder into a new one, bypassing extensions, custom preferences, and potentially problematic settings files. You will need to reinstall your extensions; your plugins will still be active.
More information in this article: Refresh Firefox - reset add-ons and settings.
Reset moves your old settings folder to the desktop. Please retain that folder for a couple of weeks until you are 100% certain you don't need anything from it.
Does it make any difference?
OK, I'll try the reset but it will be a few days away. I am tied up tomorrow and leaving for a brief vacation on Friday. I'll return on April 8 to do the Reset and will post the results.