My freind and I have a 9700Pro ver 1.1, they were purchased at the same time, Sept 02, same place and look identical.
On his PC he would get wavy lines so we swapped the graphics cards around and with my card the lines were gone. He then changed the motherboard , (Asus PT533c to Asus P4G8X Deluxe), and the wavy lines with his own 9700Pro were gone.
I put his card in my old Asus CUSL2 and Aopen AX4R+ and there were no wavy line effects. During the tests we also changed PSU's from 360w to 550w and used different brands, used different monitors and had the PC's stripped to barbones levels but without any positive effects.
It would seem that the graphics cards were not the cause of problem but rather some motherboards are creating RFI from the HF region oscillators which are within the same range of the graphics cards data pixel rate which can also be at the HF region. While I never tried it at the time, for ppl that still have the problem it maybe worth experimenting by connecting 100 pF capacitors from the RGB, H-Sync and V-Sync to ground.