If the file cannot be decoded and the date/time looks wrong, the file may have been generated using a version where some of the desciptors were placed on byte boundaries. This was done to speed up the encoding process. It only affects these particular desciptors:
004002MONTH
MONTH
0 0 8
004003DAY
DAY
0 0 8
004004HOUR
HOUR
0 0 8
004005MINUTE
MINUTE
0 0 8
004006SECOND
SECOND
0 0 8
004043DAY OF THE YEAR
DAY
0 0 16
005002LATITUDE(COARSE ACCURACY)
DEGREES
2 -9000 16
005003ALTERNATE LATITUDE
DEGREES
2 -9000 16