Problem with VGA to DVI

[faraday]

Hi,

I have an LG LCD that only supports HD trough it's DVI port. As such, I use a VGA to DVI converter to use my xbox360 in it. It works great with games etc and I have my res at 1280x736 or something like that, and it works great. However, when viewing DVD's or HD-DVD's, I can sometimes see an horizontal/diagonal wavey effect moving in the picture, specially with solid color backgrounds. It seems to be some kind of interferenc, at first I tought it could be the VGA to DVI converter so I plugged the DVI/VGA cable that came with the tv and used the gender changer connector to plug that to the xbox vga cable. But still it happened.
Anyone know any other reasons why this effect can happen? It can be extremly annoying. Thanks.

[shabby]

Im pretty sure thats caused by the analog vga signal, have you tried using component cables?

[faraday]

Unfortunatly my LCD won't output 720p via component, for some reason...

I also have tried removing all interferences (wireless speakers, wireless router, modem, heater, speakers etc), from the vicinity of the TV, I also changed the power outlet and still no go. However the frequency of the interference seems to have changed to a high frequency signal (smaller waves, but more waves), moving horizontally. Also this interference isn't constant, it seems to be cyclical. (one moment the image is fine, then waves, then fine, then waves..).

I also tried tightening/lossening the VGA cable adapter while looking at a paused image, seems to have no effect on the interference so I believe the cable may not be at fault. (or at least not just the cable). I will try later on to plug in a pc using the same DVI to VGA adapter to see if I can reproduce the interference.