That doesn't sound like normal behavior at all. You should be able to use the PVR functions with any channel you get aside from the dish home and instant weather opentv aps. I have two of the 501's which are the younger brothers to your 508 - identical in all respects save for smaller hard drives and I'm not limited with PVR functions on PPV. Try resetting the unit with a front panel hold of the power button for 5 or 6 seconds and if that doesn't fix it, I would say unplug the power from the receiver for a good 10-15 minutes and see if that doesn't resolve it. Otherwise call in to tech support and let them know you are paying for functions that aren't working as they should.