After a suspend/resume, my Dell laptop's brightness can't be changed. kernel 2.6.22-8.fc7 It's also possible that it's a BIOS issue, as the brightness keys are also supposed to work in hardware, and don't seem to do so. rmmod/modprobe the driver doesn't make a different either. The hardware is a Dell Latitude D420, BIOS revision A04 (A05 only fixes a Wake-On-LAN issue)
Works fine in F9 now.