I was also wondering if the user had taken codes from one of the AVR-5800 CCF files that is in the classic pronto files section. Some of those codes were simply bad encodes and only specified one-shot (not repeating) codes.

The other issue is possibly if there is more than one action in the action list (or linked action list) which, makes the button a "macro" and therefore, no IR code will ever be repeated except possibly if the 'Duration' is adjusted to a long value (this would need to be tested).