FF gave me such fits I finally switched to google chrome.
I know, i know i’m in league with soros, the chi-coms and the bilderburgers now ....
I had a lot of trouble with any version of FF higher than 3.15 running on Linux; video freeze-ups and at-random crashes, mainly. Turned out I had some bad RAM and the later (larger) versions of FF were accessing those addresses, where the earlier one wasn't. If Chrome irritates you enough (and I expect it will, the human engineering is terrible), try new RAM and FF4.
Same with me. I had used FF for about 10 years but in 2010 it started having too many problems. For instance it would not allow access to the comments posted on Mish Shedlock's site. I switched to chrome. Chrome won't allow you to right-click on a web-page to email a link, and right-clicking on an image does not immediately show the source URL, but other than those 2 things it's acceptable. FF seems not to have recovered to what it was before 2010.
I was just starting to use Chrome after being an early adopter of Firefox and loving it. However, the Google ads that ran recently about “It Gets Better” have made me find alternatives in lots of places.
I am not one to tell everyone to boycott this and protest that, so to each their own. However, that ad was so in my face as a decent, Jesus-loving Christian that I am actively modifying my behaviors in this case.