Remember that issue I had trying to install Leopard? (This issue.)
Since the problem seemed to stem from my multiple partitions, I just copied everything off of my Windows partition to my FireWire drive, zapped the partition and stretched the Mac partition back out (you can easily do this with command line tools in Tiger and Disk Utility in Leopard, which I had installed on that very same FireWire drive), and it worked just fine.
So. Waffle. Now spotty.
Wait. It’s always been spotty.
Waffle. Now regularly backing up.