I have been try to have my Pronto TSU2000 learn the commands for a Scientific Atlanta Digital Music Express (DMX) remote. It is a CD-Quality music service that comes through my cable.

I was able to train it to learn the channel selection keys (1-0) but every time I try to get it to learn the Power button the Pronto "fails."

Why won't it learn this command? What can I do to solve this problem?

Have you checked out B2-01 in FAQ [Link: remotecentral.com]

also
[Link: remotecentral.com]

I had a similar problem with my pioneer LD player and a Marantz 5000i. In my case, the remote would show a successful operation, but then would not operate the player.

Fortunately, my TV learning remote could learn the LD commands OK and was also able to teach them to the RC5000i. I used this as a workaround, it only took a few minutes more to do the whole remote.