I have been a SD1 user for quite a while. Over the weekend I finally found the time to upgrade to SD2. Everything went smooth except for the satelite radio issue. The issue is that SD will not let you choose the sound card and line in for the radio. Without this, the program doesnt know which line to mute when switching back to other media.
After fighting for hours I stumbled upon a solution (Dont ask me why it works, all I know is that it does). First, I completely uninstalled and reinstalled SD2. I then replaced the config directory (My Documents/Streetdeck/Config) with a backup copy from my install of SD1. After that the sound card and line in were no longer grayed out in the configuration menu.
The only other note is not to install the new update. Once I did that, it stopped working. I attempted to replace the config directory again, but that no longer fixed the issue.