Not sure how helpful this will be but I have XM and I have always used XaMP Desktop and then Studio http://xamp.imomo.net/download.php to listen to XM online. Ever since XM and Sirius merged many Sirius channels were added…
You need an XM online account to listen but they may have made it available to Sirius users as well. I tend to doubt it but it’s worth a shot. You can check on XM’s website first, http://www.xmradio.com to see if you can listen online. If you can listen there you can also listen with XaMP.