The BIOS detects UDMA2 for the Maxtor and i cannot set anything
above it.
If the BIOS is detecting mode 2 and mode 5 isn't an available BIOS
option, I doubt that XP was ever truly using mode 5 pre-SP2. SP2 does
not change BIOS settings nor can XP force a data transfer mode the
device does not support. Around the same time you installed SP2, did
you happen to:
* Perform any BIOS tweaking or upgrading?
* Changed any mobo jumpers?
* Changed the drive firmware?
* Move around the drive(s) i.e. changing what IDE channel or
controller it was installed on, moved it from Master to Slave or vice
versa, etc? ]
* Made any other hardware configuration changes to your box?
Those are the only things I can think of that could possibly - and
even then its a stretch - cause the BIOS to now detect an IDE device
now as mode 2 where previously it allowed mode 5.