F8 + external monitor key: laptop freezes

[Huub]

Hi,

I'm using an Acer Aspire LMi 1350 laptop running F8. Previously, I used 
to switch to an external viewer (monitor, beamer) without any problem. 
However, since the upgrade from FC7, the laptop hangs either immediately 
or shortly after I press the switch-monitor key. Yesterday, it turned 
out to be real disaster since I had to give a presentation (OOo Impress) 
which runs very well...but as soon as I switched the laptop froze and 
had to be switched off and on. This repeated 3 times. Then I gave up 
switching and used only the laptop (group wasn't that large..).

Any idea what might have changed in F8 for this behaviour to happen?

Thanks.