Can't stay logged in

Hi, i've been having this trouble today where on reboot Gmail logs me out and Google forgets settings such as 'Safe search' etc. but all the other sites kept me logged in ok.

i have since installed IE 7 and found i had to log in to all my forums again. after rebooting i am logged out of all of them. i selected remember me on them all. it didn't ask me is i wanted IE to remember my details.

i'm running XP sp2.

thanks for any help
James