Windows Me: new slave drive in WinME triggers ms dos compatibility mode

new slave drive in WinME triggers ms dos compatibility mode

I installed a Maxtor DiamondMax 9 80GB hard drive (6Y080L0) on a machine running WinME, and it started up in MS-DOS compatibility mode.

The drive was formatted to 2 FAT32 partitions on my own WinXP machine (worked fine there), then transferred to my mum's PC, as a slave drive.

As far as I know, the drive itself is fine, as it worked on my machine on IDE, worked on mum's in a USB IcyBox enclosure, and on mum's as an IDE slave within Knoppix, but under Windows, it runs in Compatibility mode.

Her Mobo is an Aopen AX34 Pro, VIA Apollo Pro133A chipset. I've tried previously suggested things on sites, but neither "NoIDE" nor "BAD_IDE" are in the registry.

As far as I know, the BIOS (R1.13) doesn't have any problems with 80GB, and WinME doesn't. I've tried the VIA drivers (both latest Hyperion and the old ones they said worked better with the Pro133A chipset), still no avail.

It did go dodgy when I looked in the IOSUBSYS folder, actually it hanged when I tried to open it, and on reinstall of Windows, it hanged on backing up system settings.

Anyone have any ideas?