I have freshly installed CentOS 6.2 on a DELL Latitude D420 and all seems going to be well - except for one critical problem: When I close the lid, the laptop goes to sleep, despite the settings in Power Management Preferences
[On AC Power]
Put computer to sleep when inactive for: Never
When laptop lid is closed: Blank screen
 Spin down hard disks when possible (unchecked)
Put display to sleep when inactive for: 30 minuts
Set display brightness to: 100%
[v] Dim display when idle (checked)
Yes, the power cable is connected!
Any idea how to solve this problem?