bad interaction with virtualbox

Recently, virtualbox is not playing nice. When I login, settings/multimedia shows phonon using 'default' which works fine. When virtualbox is started, it reports it 'can't open audio device' or something like that. I then see settings/multimedia lists a bunch more devices. These include: hda intel (alc268 audio) hw:0,0 hw:1,0 hw:0,6 in addition to 'default', which is now grayed out. And, now knotify4 is using 100% cpu.