I realize now what it's doing.... I programmed, for example, "00566" onto M1. In CBL/SAT mode, as mentioned, it does 8-second rewind or "A" or whatever. In Theatre mode, it changes the CBL box to channel "005" and then "66".... :-)

I want to use Theatre mode because it shows all the keys I want. CBL/SAT, device 1877, only shows the DVR keys when you "scroll" to the next page. In Theatre mode, they show up on the 1st page.

That sucks.....