Sorry this is a response to an OLD post, but I have a Kenwood VR-6060 and I had this same problem.
After tons of googling/searching I finally came across an answer that turned out to be the exact same problem and solution for me to EASILY fix this intermittent display problem.
search for this and you will find the link that saved me: "just answer Kenwood VR-615 AV Surround Receiver"
the page comes up on justanswer.com
just in case that page changes or goes away, the deal is this:
check the solder joints on the FL display board.
basically take off the top of the receiver, unscrew the front portion of the receiver and flip it up, don't remove the front panel board, just inspect the solder joints running along the display pins. (LOOK EXTREMELY closely or with a magnifying glass, etc)
the outer pins on the VR-6060 are the power to the heater for the FL display and those are the most likely bad solder joints.
carefully re-flow any solder joint that is looking rough and fix it..