"Invalid input device" after leaving the PC

[Mike Guilmot]

Hi all,

I've been struggling with this message for many months now. And I
don't know in which direction I should look to find the answer.
Sometimes I get this message on my fairly new Acer monitor (in Fedora
13 but had it in F12 also).
It never happens straight when I boot the PC.

When I boot the PC, everything is working fine. I get the gui and can
use any application just fine.
However, sometimes, when I leave the PC, and close my monitor with the
power button, and come back a few hours later, when I hit the power
button I get this nasty "invalid input device" message dancing around
on my screen.

To me, no logical explanation, as sometimes it happens (once every 10
days - 2 weeks), and other times it just doesn't happen.
Thought it might have to do with screensaver, but I tested that part
out a 100times, and never been able to do it "on purpose".

Anyone an idea where to start looking ?

TIA !

-- 
KR,
Mike