Quite often when I go from my Watch TV activity to my Watch Movie activity I get no audio. My PS3 is hooked up via HDMI to my Panasonic SA XR57 receiver to the TV, and when this happens the only way to fix it is to switch to a different input and back, or turn the receiver off then on again. Obviously it would be nice to keep this from happening in the first place, but it seems to be random and inter-device delays don't fix it, so is it possible to program a macro to power-cycle the receiver or switch to CD then back to DVD and assign it to a softkey or something?

You can map any command (including the PowerToggle, Inputxxx, etc.) to any hard of soft key by using the Activity Customize Buttons. You can also assign a sequence of up to 5 commands to any key (soft or hard). The "Add Sequence" feature is also under the Activity Customize Buttons.