i have a similar, as well wide-spread problem with my mbp 3,1. keyboard falls asleep after a couple of minutes not in use. the first two or three characters typed are not being recognized. this may not seem like a biggie, but it is actually terribly annoying. you always have to check for missing characters while writing. emails don't reach their destination because of incomplete addresses. you get 404 pages due to mistyped web addresses...
i had a keyboard firmware update, a replaced keyboard as well as a replaced logic board. no improvement. i thought maybe i could get used to it, since i definately don't want to be without my computer again for a week or more, just to get it back with the same unsolved problem. but i can't. it's just too annoying. any suggestions? i'm still on applecare, btw.
cheers