skaven

A "Corrupt Master File Table" means your partition table (or possibly the file allocation table within one of the partitions) is hosed. Not sure why switching to a new motherboard would do that, but I've certainly seen stranger things. If you're not having any luck with file-recovery utilities, then my last resort would be to use fdisk to re-create the partition table on the drive. Fdisk will only write to the partition table, so whatever files you had on the partition *might* reappear if the partition table gets fixed. This has only worked a couple times for me, so it's kind of hit-or-miss. If your drive had been flaking out on you already, then you might be dealing with a toasted controller, in which case you're screwed.

You might also try swapping out the IDE cable...that's also worked for me once.