There are quite a few people having problems with the new Mozilla Firefox v0.9 release.
I did as instructed and made sure to not install in the same folder as the existing Firefox v0.8 install. It has been working fine since Tuesday, but all of a sudden it refuses to start and I get the new error notification wizard pop up prompting me to send crash info back to the Mozilla developers (which I did the first time).
After checking the Mozilla Firefox Forums to verify that it is not just me (seems to be a lot of people with similar problems actually) – I thought I’d try what some people suggested… uninstall v0.9, and then try and completely remove all traces of all versions of Firefox (and Firebird and Phoenix) from my system. This included trawling through the registry for any reference to Mozilla – being careful not to destroy my installation of Thunderbird in the process).
After doing that and cleaning up the Documents and Settings directories thoroughly, followed by a few reboots, I was pretty confident there was nothing left. So I took a gamble and reinstalled v0.9 again.
So far so good !
So, I’m still on v0.9 for now, but if I have more problems, I might have to downgrade to v0.8 – which will be a pity (but that worked very well for me for the last couple of months, so it’s not that bad).