Most likely the issue is something in your Firefox profile is not fully compatible with Firefox 4. You might find that the problem persists after reverting to Firefox 3.6, but you can try it.

Here's the process to roll back:

First, I recommend backing up your Firefox settings in case something goes wrong. See Backing up your information. (You can copy your entire Firefox profile folder somewhere outside of the Mozilla folder.)

Next, download and save Firefox 3.6 to your desktop for future installation. http://www.mozilla.com/firefox/all-older

Close Firefox 4.

You could install Firefox 3.6 over it (many have reported success) or you could uninstall Firefox first. If you uninstall, do not remove your personal data and settings, just the program.

Unless you have installed an incompatible add-on, Firefox 3.6 should pick up where you left off. If there are serious issues, please post back with details.

Note: I haven't actually tried this myself!

It is easy to do see

• installing a previous version of Firefox <-- clickable link --

However in addition to considering downgrading you could consider upgrading. You would appear to be using version 4, version 5 is now out, and the main changes have been fixes to problems.

You could also consider starting a question about your crashes because none of the standard released versions should be crashing on a regular basis.

I hope that one way or another you solve the problems you are having.

I am going back to FF4.6 for the same reasons as the comment above. My desktop recently upgraded to FF5 and is utterly useless to me now. The only way I could post this was by using my laptop, which, thankfully, is still on FF4.6

I see no reason why Firefox 5 would prevent you using this website. If you have problems with this forum they may still occur if you downgrade.

Note on the subject of Firefox 5 there is an add on [compatibility reporter] if your problems are related to add-ons that worked with Firefox 4 but will not work with Firefox 5 it is possible downloading and running that add-on may resolve the issue.

Official policy is that Firefox 4 is now unsupported, insecure, and should not be used. Downgrading should for now be to Firefox 3.6 ; but that may not be supported for much longer.