I was testing w/ some disks that appear to have bad partition
tables and was getting the following error messages:

SCSI device sdt: 35566480 512-byte hdwr sectors (18210 MB)
 sdt:<4>  Warning: Disk has a valid GPT signature but invalid PMBR.
  Use GNU Parted to correct disk.

Unfortunately, that's not where the problem stopped.  I got
random pointer dereference problems, and was apparently having
data structures freed out from under them.  Turns out the
find_valid_gpt() was freeing data structures more than once and
passing back pointers to freed structures.  Patch below.

	Alex

--
Alex Williamson                                  Linux Development Lab
alex_williamson@hp.com                                 Hewlett Packard
970-898-9173                                          Fort Collins, CO