TGTRLS question

I've had a user download our zip product and try install it on a V5R3 box. The objects were created on V6R1 with a TGTRLS of *V5R3 and were saved for an earliest release of V5R3. There are six objects shipped - 4 restore and 2 don't. The 2 that don't are programs. These two programs have been optimized but I'm not sure if that would cause the problem. Anyone have anything to suggest I do? Here's a snippet of the error:

RSTOBJ OBJ(*ALL) SAVLIB(ARPZIP) DEV(*SAVF) OBJTYPE(*ALL) SAVF(DLT/ARPZIP)
PGM ARPZIP not restored to ARPZIP.
PGM ARPUNZIP not restored to ARPZIP.
4 objects restored. 2 not restored to ARPZIP.

Additional Message Information
Message ID . . . . . . : CPF3888
Date sent . . . . . . : 18/07/12 Time sent . . . . . . : 18:04:00
Message . . . . : PGM ARPUNZIP not restored to ARPZIP.
Cause . . . . . :
If the object is a database file, an unexpected failure occurred during
the restore of a file member. The member was not restored.
If the object is not a database file, then the conversion needed to make
the object compatible with the current system is not possible, so the object
was not restored.
If the object is a program, module, service program, or SQL package, then
either the object may not have the required creation data needed to perform
the conversion, or there was an unexpected error. Conversion of these object
types during restore is controlled by the Force Conversion on Restore
(QFRCCVNRST) system value and the Force Object Conversion (FRCOBJCVN)
parameter on the restore command.