Monitor gives "Frequency out of range" error

[Tommy2k4]

I've been using kubuntu dapper for a few weeks now and have had this error around 10 times, 4 of them were today It doesn't happen on boot up like most of the other posts I found with this same error. It happens for no apparent reason, although a couple of the times happened when I was taking screenshots, but other times I wasn't.

What happens is any music playing will stop, the monitor will show lots of multicolored vertical lines, then after a few seconds it will change to an error saying "Attention - 31K / 0Hz Frequency out of range". the num lock light also goes off (if that makes any difference) and pressing ctrl alt f6 doesn't bring up the console so I don't know what the problem is. I rebuilt xorg.conf using dpkg-reconfigure and (after adding 1280x1024) this is my config.

http://paste.ubuntu-nl.org/16559

Someone in IRC recommended changing VertRefresh to 30-160 but that made no difference either.

I don't have a screensaver on either.

Thanks, Tommy