display problem what could cause this

Driver maybe (not likely)

Jiggle your connectors from the LCD and to the computer - also try alternative inputs (if that LCD has any)

Or it could be a crap video converter / bad RGB driver.

If jiggle no worky, return.

Change some of your settings, change colors from millions to less, and calibrate the display as well. (afterthought)

But that looks very similar to an LCD I had at work that died on me.. (it was an NEC)

 

Yeah that looks like a hardware issue, not a software one. But you could try re-installing Mac OS X. Or at least, boot from a Mac OS restore DVD or install DVD, and see if, after booting from that, it looks OK. If not, definitely a hardware problem, because there wouldn't be a driver problem on a restore/install DVD.

 

Thats a bad LCD, you would want to replace that, again it sounds...