I am not sure if the xmradio website changed anything or not but on my Windows machine I use XAMP Studio and that stopped working two days ago.
When it happened the xmradio website was offline for maintenance and when it came back online, the online interface worked but the XAMP Studio application didn't.

I just assumed they changed something on the site due to the new Sirius content but I haven't looked into it yet.

I would check around some forums for XAMP or other custom apps that stream XM and see if they are still working or not. My guess is that all apps are affected.