monitor zig zagged crazy!!

[tape]

XPpro 3 GHz, 1.5 Gb Dell 4600 Gateway 21" LCD (6 months new). I am getting strange zigs & zags on monitor. Sometimes showing up in active windows as segmented lines.
I first noticed problem yesterday while listening to podcast in iTunes. Video & sound not in sync, even though no other app running. I changed a few settings in prefenrence to view podcast in same window as iTunes. iTunes locked up and everytime I restarted, the main window would open and then freeze. Like I said, this was the first notice that things were out of wack. I discoved the iTunes library was the casue of my problems. I reinstalled an earlier verison of iTunes, copied over an older iTunes library and that solved the frist problem, then during that process, the monitor kept going crazy. Finally did a repair install of XP, reinstalled drivers for video card. Seemed to solve the problem, but it still zigs & zags now and then, sometimes just in a new window that spreads to the whole system. I'm considering a complete clean install of the OS, but I just did that a month ago and don't really want to spend the time. Any suggestions or ideas what may be happening? Thanks.

[Garyfl]

Can you hook up your monitor to a friends machine and see if it does the same thing?

[tape]

After my initial posting, monitor has been just fine. Still can't get latest iTunes to run, but that is another issue, isn't it. The only thing besides reinstalling the drivers that may have done something was to detach and reattach monitor cable. Sometimes the simplest thing.