strange video cutouts?

[Tom Horsley]

I've just been getting latest updates on my x86_64 FC6t3 box and
downloaded all the extra screen savers to check out the madness,
and noticed this weird behavior:

Quite often (especially when looking at the 3d screen savers), my
video will apparently cut out for a fraction of a second, then come
back on. It seems to do this two or three times when I first
switch to a different saver in the list in the screen saver
dialog (I don't have to be running the full screen preview).
After it has done it a few times, it seems to get over it
until I switch to the next 3d screen saver.

It almost acts as if something is triggering the DPMS video
shutdown momentarily.

This is with a pcie radeon X700 Pro video card and the
radeon driver from xorg.

Anyone else seen these mysterious cut outs? Anyone know what
component to report something like this against (screen saver?
video driver?).