This is the problem I had last night...this is what you need to do..
log into
https://home.sirius.com/manageaccount.do
Using your User and password for Sirius and then the number/letter challenge oin the window
That will bring you to 'My Account'. If you haven't already, you the need to sign up for Internet radio (button on left/bottom of window of says 'Add Sirius Internet Radio')
Once you go through this process (get the free one don't do the pay one) then you will have to provide a NEW user name and password just for SIRIUS internet Radio.
Now, if you already signed up then info (user name) will show on the bottom of the 'My Account' page.
like this:
SIRIUS Internet Radio
Click on the username below to view or change your internet radio login information. A Master login type has access to all of your account information. A Service login type has no access to any of your account information.
Username ESN Current Active Service Login Type
XXXXXXX 0043643XXXX Free Online Listening Service
THIS INTERNET RADIO user/pass you either just created or is at the bottom of the MY Account page is the USER AND PASSWORD YOU HAVE TO ENTER INTO USIRIUS.
I was trying to log into USirius using my regular Sirius user and pass that just wont work.
Then go through the steps on Orb etc. Make sure that when you copy over the URL's you use the MMS ones from USirius. Oh and check that you have either firewall turned off or set up for port 80 on your home network.