Errors such as 30, 69, and 527 were seen on c-tree data and index files in FPUTFGET mode.
When closing a file that has its update flag set, there is potential for corruption of the header information in FPUTFGET mode. A loop was not correctly locking the header before writing a new value in rare situations. This caused updates to the header to be lost, resulting in a variety of errors. The logic was modified to correct this situation. Note that this only applies to FPUTFGET operations.