So I guess you are operating on some broken version of 2.6.21-rc6-mm1 codebase if you are getting rejects on this trivial patch.Didn't think of that - the codebase might be wrong.
I don't know about 2.6.21-rc6, but 2.6.21-rc7
Anyway, based on information you have provided in your later messages, it seems that it is probably not necessairly related neither to USB nor HID, as you are getting hangs at different stages of boot, depending on your local configuration/kernel version used.
Is vanilla 2.6.21-rc6 ok? If so, would you have time to bisect the offending patch?