I too have the Kenwood VR-507 with R0720 remote. I've had this set up for about 3 years, give or take, and have been having the same "won't work" problem for the last year or so.

Remote works great on all of my components except the receiver which is hit &miss (at best), but getting worse all the time. I'd pretty much resigned myself to having to get up & do everything maually.

I tried the tapping trick, and as amazing as it sounds, it works fine after tapping the bezel. As Eightysix said "works every time".

But this still isn't going to stop me from tossing it in the landfill as soon as I get a new receiver!