Scott,
Unfortunately, your commands should be work (meaning those discrete commands are correctly strucured and on the correct device codes/protocols).
Some DVD's, CD's and VCR's will turn On from Off using the Play command. If so, a macro Play/Stop=On and Play/Power Toggle is Off.
You might also go to the Nirvis sLinke discussion group
[Link: groups.yahoo.com]. They are really into controlling Sony CD Jukeboxes and may know something more.
Sorry, I can't be more encouraging but if you do ever solve the problem please let us know.
-Jon