Just found out that by 'echo sth_wrong > /sys/power/state' the kernel would 
oops in a fatal way (no clean exit from there).
The oops suggested that the code would enter an invalid fn.

You may apply the included patch to solve the bug. IMHO doing a clean exit is 
much preferrable than having BUG() there.

In the patch I also added some double checking of the fn. You may disable that  
(although sleeping is a one time fn which won't be slowed dow by that). 

Status report:  (HP Omnibook XE3GC)
S1 ('standby') works
S3, S4bios will suspend, but NOT resume.
that's the same as previous kernels I've tested so far.

I still have the ALSA-artsd deadlock I reported w. -test1 (in short, artsd 
resumes from S1 in a 'disk I/O' process state, which deadlocks maestro3)
see: http://marc.theaimsgroup.com/?l=linux-kernel&m=105836807605512&w=2