I have a Denon 3808. Back in 2008 there was a lot of discussion of this ussue on both the 3808 and XBR4/5 forums. The problem would vary quite a bit from setup to setup. In my case the interruption would consist of loss of video and most often (but not always) audio for about 2-3 seconds. Frequency would vary from as often as every couple of hours to every 3rd to 4th day. Some people had this much worse getting to the point where their systems sounded to be almost unwatchable. I believe I also found some references to similar issues with some Samsung and Sharp units. I'm not sure if anyone ever definitively determined if it was primarily a Denon problem or what.
The splitter trick was discovered by one of the guys from Canada. I tried it after he had no problems for a couple of weeks and it took care of the issue for me. I've been without any handshake issues for over 4 years now.