Guys, this might help you. might not. I have I9000M (Bell), just received replacement phone from Samsung today. Had same problem with stuck buttons. I've tried method from 1-st page and also lost both buttons as some of you! Then I've tried re-flash JL2 twice! It didn't help! I still had no buttons! Then I went to the same menu, and clicked again "Touch key FW update" - I had nothing to loose anyway
But surprisingly I've got my buttons back and it seems they don't stuck anymore!
And it seems the phone is waaaay less sluggish now! Don't now if it'll last though
I can't believe how lousy this phone's firmware, despite it's great phone
Update Feb, 14 - the problem never showed up again, so it looks that if it's been fixed, it fixed for good.