I have 2 activities that use my JVC receiver. In one activity I would like the channel +/- buttons to control my SubVol+ and SubVol- commands from my receiver. When I program the first activity to do this, then go to the button layout for my second activity, the channel +/- buttons are automatically set to SubVol+ and SubVol-. What gives? Do custom button mappings in activities that share a device stay the same for each activity? Is there a way around this?

You should be able to go into "customize" for a given activity and manually choose what the channel +/- buttons do.

Yeah, I know, that's what I do.
I have two activities: 'PVR W/Rcvr' & 'XBox360 W/Rcvr'. If I try to customize the buttons for 'XBox360 W/Rcvr' and set the Channel+- buttons to be SubwooferVol+- and save, then go to the customize buttons page for my 'PVR W/Rcvr' activity, the Channel+- buttons have the normal TV Channel +- buttons assigned but also SubwooferVol+- are mapped as well. Is this making sense?

It's a feature to avoid having to manually set the same buttons in every activity. It will propogate the commands to any other activity that use the same device for the same function. You can avoid it by learning the commands to your PVR device and Xbox360 device and mapping those to the channel +/- buttons. Since those are only used in that one activity (I'm assuming) they won't be propogated to any other activities.

Thank you very much for the tip, akirby. I will give it a try.