[banzai]

This has nothing to do with any software player. It´s nearly always a sound hardware / driver issue. Playing BG while having a player running is like having two software players running at the same time. For the hardware / driver combo it doesn´t matter if one is a player and the other a game or anything else.
Most consumer sound hardware / driver combination isn´t able to manage different sources (programs) at the same time. If you´re lucky one wins and gets exclusive use of the device - if you´re *not so lucky* sort of a race condition can develop (the other extreme) and the whole system locks up.