radio turns on by itself a little while after engine shut off

What is your question?

My radio (and everything else) mostly works, but turns on by itself after I turn off engine. Fiddling with the power/volume control will turn it on and off (no need to push button). I "fixed" it by taking out COMAND fuse in trunk. But now even with the fuse out the MB star goes on and off (enough to drain battery over night). Anybody know what is broken? MB dealer says replace COMAND unit; somebody else says it's the audio gateway control.