the following is true for the asus a7v... I have no idea otherwise
install on the ata66/33 controller, then recompile your kernel, and in xconfig, go to block devices and change other ide controller support (something like that anyway, can't remember) to Y. save and make dep.. make bzImage..make modules... make modules_install... copy your image to boot, configure your boot loader, and make the switch. should be happy. if not.. pull out your hair and try the 2.4.0 kernel, if that doesn't work.. pull off your head, and be happy with the ata66 controller