Weebyx:
So it is not the tape input, although i think it is funny that if the BM7000 is set to aux, and i turn on the airport on tape1, then the sound from airport can be heard at the same time as the tv/aux input. But maybe this was B&O's way of just skipping corners since none of the other devices from the 7000 range could play at the same time.
Does anyone else that own a BM7000 confirm that this is true ?
No it isn't. It's technically impossible with the way the program selector is implemented. The only way this can happen is that you are playing the AE into the tape outputs, i.e with a cable wired for the wrong direction as mhw suggested.
Forget about the Wikipedia page (I find those pin number explanations in words incredibly hard to follow) and look closely at the actual DIN plug. They usually have numbers beside the pins, and if it doesn't, compare to some original B&O cable, which do. I'm almost sure you'll find that it is actually wired to pins 2, 1 and 4.
Or, try connecting the AE to the CD input. It doesn't have the output direction wired at all, and you probably won't hear a peep.
*edit, and rant mode on*
I mean, the Interwebs are full of all kinds of DIN connector pinout pages, one messier after another, and none of them bother to provide a simple 3D view you could compare to an actual plug in your hand without thinking twice. So, to save the mankind from hours and hours of frustration, I hereby provide this totally groundbreaking graphic:
