using an ATA66 cable shouldn't make a difference, except for maybe a cleaner signal (less crosstalk). The device you have jumpered as master is on the end of the cable and the device you have jumpered as slave is in the middle, right? With the ATA66 cable you could try setting both for cable select. But with your bios seeing both drives it's probably just windows getting confused. I've seen the problem you're having mostly with people who have an SBLive, but you don't have one. I read somewhere that this can happen because windows re-assigns an IRQ to a device from what the bios set it up with and another peice of hardware gets bumped, usually a cdrom. It happened with me on both my KT7-RAID and 8K7A+, I just moved my cards around until the drive showed up in device manager.