Just thought I would post and share my experience.
I have had a VR-507 w/RC-R0720 remote for about three years now. After the second year (warranty had just ran out) the receiver stopped taking inputs from the remote. It would continue to play but would not accept inputs from the remote mentioned above or a universal remote that came with my satellite reciever. The front panel will continue to accept inputs.
I assumed it was heat also and ran the system with the cover removed. No change. It would work just after power up and then stop working only to work again later in the day. I grew tired of this and had a service shop take a look at it. They quoted a 140-160 repair bill to replace the microprocessor and reset chip.
From the posts above, it looks like Kenwood has a problem with their product. I am going to call 1-800-Kenwood and talk to someone in their service department. Maybe you guys would like to do the same.