In case this is bugging anyone else, try checking box opposite way to what you want first; restart; check it as desired:mad: :mad:
(Solution to my equivalent tab problem given by Bugzilla crew):p

I got information about a bug in FF2 that when you are asked to upgrade, and answer positive, after downloading and installing upgrade, your software actually gets Downgraded to FireFox version 1.5.0.8
If in doubt check the version as follow:
Help > About dialog box. Should show: FireFox 2.0.
I believe it is only a bug and not much is actually changed except name. Mozilla is aware and looks to rectify it.

Have just gone back to 1.5.8. FF2 was having some sort of battle with the other greedy *** PSE4 over all the available ram, neither willing to let go.

Spelling will go back to previous abysmal level.