E53 Audio Problems... HELP!!

[lemans4.8]

Well, I finally got around to installing my new 6-disk CD changer (after 9/2005) replacing my old one (5/2005). I also replaced the radio module to a brand new one.... The radio works fine, but I have no sound coming from the 6-disk, though MP3 titles show up on the screen.... You can scroll through the MP3 titles and every so often, you'll start to hear the radio..... Then when I try to switch it to Sirius, nothing happens.... Usually, you press "mode" and it goes FM/AM >> CD >> TAPE >> SIRIUS >> FM/AM but mine goes FM/AM >> CD >> TAPE >> TAPE >> FM/AM...... skipping "sirius" and replacing it with "tape"

I checked all the wires and they are all plugged in.... My car is a 2005 with DSP, had working cd and sirius module prior to this.... I was just trying to upgrade to an MP3 6-disk CD changer.... Did I forget to purchase something??

Sorry for the lenghty post and THANK YOU for your help!!