FileVault Failed - File system not supported on Core Storage

After quite a bit of frustration getting Lion installed involving disabling FileVault 1, re-partioning my disk to remove BootCamp, and copying all of my files back, I'm now hoping to enable FileVault 2. When I try to enable it though, I get this message:

Interestingly, I've already had FileVault 2 enabled brielfy when I first upgraded and before I had to do all of the disk moving/partitioning/re-installing to remove the Boot Camp partition, so it can't be incompatible with the the disk.

Any ideas how to resolve this? I only have a single partition now and I'd like to avoid deleting it and starting over again if possible.