Can't convert tib -> vhd

Just created a backup of my Win 7 x64 system with 2010 and tried converting this to a vhd file. It errors almost instantly with:

Details: Check partition 'C:' was terminated.
Details:
Index is corrupted. (0x70025)
Tag = 0x89D94B01B483DE7E

Any ideas? Tried twice with different images but same result.