You might try manualy adjusting the timing of the output. I have found that sometimes the remote has a carrier frequency that is so far off from the receiver frequency that if they are not reproduced exactly then the activation of the code will be intermittent. When you push the button on the remote the activation code is sent repeatedly until you release the button. If the carrier frequency is off then one of the many activation codes that are received will activate the device. However when you activate a macro, only one activation will be sent. (This is only true of certain devices, i.e. a stewart theater IR controller that I have does this) in order to correct the problem the value represented in the first 4 bytes of the IR code will be modified, in my case it was to change this from a 0000 006d (approx 40khz) do a 0000 00 0070 (approx 38khz) before I could get reliable operation of the screen from within a macro. As well I noticed the the value that was learned and placed here was dependant upon room temperature and battery levels for the remotes. So, I would imagine that the same issues apply to the receivers as well, although one might believe that the receivers are more stable, it does not apply where inexpensive receiver units are used, particularly where a mechanical device (ala the stewart theater screen) they tend to be way outside of the nominal 10%.