I may be tracked down and shot for posting but...hey, if it could help. I cut this out of a post in the URC forum. I don't know if this will have any bearing on what you're trying to do, but if all else fails you could mention it to customer support if you speak to them.

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There are two different kind of IR commands, One is a code that only contains only the single pulse, the other contains a single pulse followed by a repeat sequence. This is part of the IR code not so much a function of the remote.

What you are dealing with IS a bad code. If the IR code you had on those buttons contained a repeat sequence it would repeat while you held the button, obviously the codes do not contain the repeat sequence.
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I don't know what model Harmony you're using so I couldn't check to see if it has "press and hold" functions, (which is what you would want to apply the repeat sequence to). There's lots of knowledgeable Harmony guys in here. I'm sure someone and give you a better reply. I just thought there may be another solution to your problem then just trying to repeat the single step IR code.

Best of Luck