While I'm in problem-solving mode, I'd like to pick the forum's brains
again if I may.

I have a 23" Apple Cinema Display that is normally used with the G4
Tower, also connecting a 17" display as well with the DVI to ADC
adaptor. Screen is fine.

I've recently attached the 23" via the DVI  to ADC adaptor to my
powerbook, and have since had a lot of noise/interference/buzzy lines
in some areas of colour on the screen.

Anyone know what this is?

Thanks, Matt.