Here is the message I got back from Brian from Niveus.
"Great, glad you’re enjoying it. We’re no longer actively developing these apps though – we did one update from the Windows 7 version to Windows 8 and now we’ve ceased development w/Sirius and Media Center. As a matter of fact, the Windows 8 version is not compatible with Windows 8.1. We did some development with Sirius and Android but never brought anything to market and have no plans to. There is a Sirius/Android app available from Sirius – does that not meet your needs?"
sgniwder, guess that answers your question why it won't work with Win 8.1