When carring out a SAVLIB have you changed the Target release parameter from *CURRENT TO V4R5MO?
AFAIK, if you go to V5R3 and your customers stay at V4R3, you have two choices.
<li>Drop support for V4R5 and earlier. Objects that you create on V5R3 cannot be saved to earlier than V5R1 no matter what new features you use, even if you use none.</li><li>Drop the idea of sending compiled/created objects to earlier customers. Send source code and create the objects on the customer system. For data, send flat files and use a proc that you pre-install to read the flat file and convert the data into the formats appropriate for the customer.</li>
I don’t think any other choices exist.