notebook freezes

My few days old -current freezes if I press Fn-F6 (this is the combination to 
adjust display brightness) if I've done a suspend/resume before. Directly 
after boot it works fine.

This key combination normally works without any software support, so I don't 
know why it freezes the notebook.

I don't know when this started exactly but I thinks it's been there for a few 
weeks at least.

Any suggestions what commit could have caused this (I want to avoid binary 
search of the cvs tree if possible)?

I tried with GENERIC kernel with the same result. There are no warnings/errors 
displayed on the console and I cannot even break into the debugger.

dmesg can be found here.
http://stud4.tuwien.ac.at/~e0125637/fbsd/dmesg

Stefan