Hello! I have the following Tivo equipment: Tivo Bolt+ Tivo Mini Tivo Premiere XL4 Tivo Series3 HD Tivo Series3 HD Tivo Series3 HD I've most recently set up the Bolt+ and Mini because Comcast is going to MPEG4 and I'm starting to lose HD channels on the older boxes. All of the equipment is on my wired network. The wired network is protected by a SonicWall TZ 300 firewall which is connected to my Comcast cable modem. I'm finding that I can't transfer shows from any box to nay other box. When I try, the boxes say that they can't connect because of Tivo error C423. I've forced connections to the Tivo service and they work; I've done it multiple times. I've rebooted boxes in various combinations. The errors persist. If I do a port test on the Tivo diagnostics screen, the tests pass. All the network tests pass, though they vary from model to model--DNS, network resolution, whatever. The Tivo can't discover any problem for itself ... until I try to transfer a show. The Mini can watch live TV with the Bolt+ as its source. However, it also can not read already-recorded shows from the Bolt+. I also notice that the devices list each other in the "my programs" display (or the "my devices" display, or ...) without a problem. That is, they're detecting each other just fine. But they're failing to handshake, or allow the exchange of media when I want to browse the content on one box to play on another. The Tivo documentation for the problem is painfully vague and unhelpful. What other things can I do to troubleshot this issue?