Blue and yellow hashes on 17" plastic display

[twoksl2]

I have a G5 dual 2.0 radeon X800AGP and a 17" ACD hooked up via ADC,
just recently after u upgraded to 10.5.8 i started getting funny hashes on the screen, they seem to be connected to the application, not the screen or the OS. when i move whatever window they're on, the hashes move too. when i close the window they close too. here's what i've tried

1. blow out computer and video card.
2. remove card, clean pins and reseat.
3. try different monitor (shows up there too)
4. reinstall and update
5. reinstall and not update
6. change resolutions
7. ATI driver install (10.4 one)

is there anything that i am missing or should try.
it doesn't seem to be heat related.

 

[twoksl2]

wow

wow, best mac forum on the web and nobody has any ideas?
have i really stumped everyone?

 

[tobyg]

To me it looks like classic video memory corruption. It looks as if your video card is dieing.

 

[Dr.Pants]

3. try different monitor (shows up there too).

Yep, that's on-card corruption. It could be the DVI cable, but doubtful. Have you tried the monitor on another computer? I would go for that just to make sure that it isn't the monitor. It probably isn't, though, because of what I quoted. It could also be the cable - the test on another computer would show that.