update...

I've now determined that if I go into the set-top box' settings and back out real quick, the aspect ratio button works. Same as before though...as soon as I change the channel the button no longer works until I turn something off, or go into and back out of the box' settings.

Wtf?

STill no luck on the video source button. I found in the remote's guide where it says how to program that, and I followed instructions, but it still won't work.