Firefox keeps forcing compatibilty updates in Win 7 starter

[Eyeball Kid]

I'm having trouble with Firefox on my HP netbook running Win 7 Starter. Every time I run Firefox for the first time after booting, none of my extensions work - I go to the add-on manager and it shows all my extensions with a red exclamation mark, forcing me to run a "find updates". I do this (Successfully) each time, but after the next boot I have to go through the process again. Ideas anybody? I'm running the exact same version of Firefox (3.6.2, though I had the same issue with the previous Firefox release) on two other computers, one 7 Ultimate 64 bit, the other Home Premium 64 bit, with all the same extensions with no issue.