Apologies - a bit of a brain fart. I had tried setting the duration, but I actually focused on the word "minimum" and overlooked that it was in the "duration" block. Setting the minimum to anything other than default resulted in the IR not even working in test mode, so I set it back to "default" and forgot about it. Inspired by the rather terse note a couple posts back, I tried it again - same results.

As I have noted, it works fine in Test IR mode. When I send the file to the remote and try it, Play/Pause is the only command that does not work. Interestingly, when I do push the button, my Motorola DCT6208 digital cable box flashes its display from the time to the channel and back again. It does not do that in Test IR mode.

I do not use the button in any way other than directly (i.e. - it's not used in a macro).