I had to delete my .bitcoin directory in Ubuntu 12.10, after months of getting the near 9 GB of blk data files.
I copied everything over to another machine (and back to the original too) and it gives me:
A fatal error occurred. Bitcoin can no longer continue safely and will quit.
CDB() : can't open database file blkindex.dat, error 22
bitcoin in Runaway exception
chmod +w on the files, but still no go.