Probably not but it won't stop us from theorizing. ;)

There's a lot of evidence that the Pronto NG firmware mangles some codes. There's little rhyme or reason to it. Some have even implied the individual who wrote the firmware is a practicing numerologist and avoids certain numbers considered unlucky. ;)

There's a difference in timing between the emulator and the firmware. That could be a clue that not only helps explain what you see but what others have seen with codes that will not execute when d/l to the remote.