cheers!! Kie
have tried EVERYTHING (my CS3 also suddenly stopped working with the hand space bar and shift scale stuff)...tried everything suggested, but then in a fit of futility after reading these threads, I quit firefox and went back into illustrator to see if I could resolve..... Now they are working so it must have been the 15 firefox windows I always have open.
hmmm.....
Can you provide any more information on "If you have any process open that holds a port to the internet open then the modifier keys are blocked."?
Killing boxee's remote service did in fact solve my shift-key in Illustrator problem, but your description of "any process open that holds a port to the internet open" would seem to apply to most of the apps running on my computer at the moment (web browser, email client, ssh client, etc).
This was bothering me for weeks! Thanks guys :-)
I haven't worked out which key is stuck, but I think it's F16, F17 or F18. When I pressed one of these again, the Illustrator problem disappeared.