after reading all of the posts here, most of the problems are the beta application can not get the show list from your one or more tivo device. The problem will be fixed in the later release. now for the beta2 version, there is a temporary workaround for you guys ( it works most of the time

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1 ,go to ~/Library/Preferences folder, trash or rename com.tivo.desktop.plist file, this will reset the settings of tivo transfer, won't do anything about your tivo files.
2, reopen the application, the preference window will pop up, asking for media access key, enter it. and you are ready to go.
now your tivo recordings should be seen.
if you still has no luck after steps above, please reply below.
Tried those steps and I still don't see the DVR. I have actually never been able to see the DVR. Can ping it and the DVR is connected to the network and getting downloads OK.
Was on the chat line today and they guy couldn't get off fast enough. Never had that happen on a service chat line before.
He posted several items to check. First was check the network settings on the Mac. When I asked for clarification about what to look for he sent a link to Tivo connecting to the network not the Mac.
Have Snow Leopard 10.6
Toast 10.3 and downloaded Tivo to go 2
Any help would be appreciated.
Thanks,
Jared