FC4 and G5

Hi, Is there anybody using FC4 final on an iMac G5? I have problems that I didn't have with test3 (as much as I can say after a short test period). I could install FC4, but within some minutes of using, the system doesn't respond and I get the following messages on the console: ata1: command 0x35 timeout, stat 0x50 host_stat 0x4 hda: lost interrupt mpic_enable_irq timeout ata1: command 0x35 timeout, stat 0x50 host_stat 0x4 Moreover, pushing the TAB button (tab completion in shell at the console) results in a scrolling screen and the above error at once. What's this? Zoltan