I bought a Sapphire Radeon 7000 PCI 64mb card for my beige G3. I flashed the ROM and it all works well apart from one really annoying thing. In OS9 there are graphical anomalies (lines) flashing around the cursor each time the cursor icon changes (eg wristwatch). I tried underclocking the card, but this didnt change anything - could it be overheating? OSX works fine.. but in a PM7600 (OS 8.6) the card shows glitches again... so its nothing to do with the G3.
What is the problem likely to be?
(this Radeon is pretty much identical to the ATI mac original and other people with this card didnt have this problem)