Many people have had problems with DR2.1 update 6 freezing after it beeps a few
times. This is a known bug and will be fixed in Update 7 or DR 3.0 (i assume).
Because of the new sound support, a bug was added accidentally. In the
meantime, Gary has fixed the bug in a WIP (work in progress) kernel:
> I've made a WIP kernel which should fix the "my system dies after making
> the 'whoop' sound" , etc. problems many of you have had with Update #6.
> Please give this kernel a try: