This may not fix everyone's problems using tivodecode manager with Leopard, but I was having the same problem as several of you, with failed downloads looping over and over. I figured out that leopard's firewall, which is a lot different than Tiger's firewall, was not doing the usual thing and asking you if you wanted to allow tivodecode manager to accept incoming connection. I set the firewall to explicitly allow tivodecode manager to receive incoming connections, and then it worked fine. To try this, go to System Prefs > Security > Firewall tab, select the bottom choice "set access for specific services and applications", click the plus to add a new app to the list, naviogate to and select tivodecode manager, and make sure it's in the list and set to "allow incoming connections". You could also set the whole firewall to "allow all incoming connections" but then you've essentially turned off your firewall. Hope this helps somebody...

- JonYo