Scratch that, just tried to boot into mint 11 (installed from the cover disc of LXF), gdm login screen froze so I forced a reboot, and again the PATA drives are not detected. What I didn't mention at first (I didn't think it would be relevant) is that the first time I booted into mint, it froze up and it was after forcing a reboot on this that the problem first occurred.
The drives are as follows:
80GB PATA master: Windows Vista
320GB PATA slave: Linux Mint 11 and Crunch Bang Linux
500GB SATA (socket 2): Media, although I believe my GRUB is installed on here for some reason