Fix Bollixed security certificate setting for facebook?

Question

Hi, running ff 15.0.1 on winXP sp2:
After months of using 'restart my computer' as a workaround for the "untrusted connection" error message that occasionally blocks all facebook access, I got disgusted a few days ago and tried to create an exception in the 'security certificates' dialog, but I was over my head and messed it up...
...I thought I was trying to create a blanket exception for www.facebook.com, but what i ended up with was FF REMOVING www.facebook.com from every FB url, so that when I tried to go to, say, www.facebook.com/my.name, I got an "Invalid URL" message stating that "The requested URL "/my.name", is invalid." :-(
after struggling to figure out how to fix this by searching the forums, I found a recommendation to use 'clear recent history' to undo my mistake: I cleared the previous hour, and voila! problem solved, yay!
alas, returning home from a weekend trip several days later, after browsing FB for about 30 minutes the problem has recurred, and 'clear recent history' doesn't solve it... I don't want to 'reset firefox' for various reasons. The thread at http://support.mozilla.org/en-US/questions/878694?s=clear+security+certificate+settings&r=7&as=s seems to offer a possible path to a solution but I'm having trouble sorting out the terms... is there a simple way to do something like 'revert to default security settings', or just find where my bad change is stored and reset or delete it? It seems like it should be a really straightforward 'undo' operation but I'm stymied, and don't want to mess things up even more: I have a lot of work going on in open facebook tabs and it would be a little tragic to lose it... any help? Thanks in advance!
-kc

Answer 1

I appreciate the educational links, Cor-el, but they seem like unsatisfying workarounds that disable key features of FF and/or FB without actually addressing my question, which was:
"is there a simple way to do something like 'revert to default security-certificate settings', or just find where my bad change is stored and reset or delete it?" [without doing a "Reset FireFox"]
...the problem 'went away by itself' within an hour, but has recurred twice since then (for brief periods)
Cor-el, I use autocomplete-url as a regular part of my navigation, and I LIKE having a secure connection to facebook, so I don't want to use these workarounds that disable key features of FF and don't actually address the 'wierd behavior'. Since I see that you're a big contributor in this forum, I'm guessing the fact that you offer no better suggestion than this may mean that we're looking at a bug or at least a major glitch. I acknowledge that this COULD be a FB issue, or even a "User is an idiot" issue, but I'm pretty sure it's a fouled path to re-edit my FF security-certificate settings.
If anyone cares to review the original post and try again, I'll appreciate it. I consider this ticket still open :-)
Thanks for all you do,
-kc