I hope this message helps someone else who runs into a similar problem that I just had with my Rocketfish 4 port HDMI Switch. I have had a model RF-HDMI4 for about a year now. I have only had 2 components (a comcast HD-DVR and a Sony Blu-Ray) connected into it with the output to a Samsung Plasma TV. I bought the switcher from Best Buy and although I didn't need a 4 to 1 it is what they had so that's what I bought. I had been connecting the DVR into port 1 and the blu-ray into port 2 and all has been working just fine until the other day when I switched to the All Room DVR from Comcast. Port 1 quit on the sound and the video intermittently black out for a few seconds at a time. I tried several things with the remotes, called comcast, and as a last resort started switching around the cables on the switch box. I moved from ports 1 and 2 to ports 3 and 4 and everything is fine again. Good audio and picture. Go figure. Whatever I try through port 1 now has no audio and I think it was just a coincident it happened at the same time as the DVR switch. From what I've read, it doesn't sound like having a port in a switcher go bad is all that uncommon.