No, the lines do not seem to move. The problem only effects some avs, signatures or an attached image. The pics in the gallery get messed up to. Not all of them. Only a few. It is not just this forum though. The same thing happens on Imagestation.
I have a Futura monitor, 800x600. That is all I know about it.
I think the video card is ATI 3d Rage IIc APG Graphics with 4MB SDRAM.