Wild shot: a thing you could try: I removed all Adobe Reader stuff, in favor of Foxit reader. Also editet mi host file so that all adobe traffic refers to my internal IP 127.0.0.1 address. Adobe seems to hamper firefox, and might be that with a (loaded?) browser some adobe plugin like flash etc interferes with your audio. I have flash still running, but if i watch some youtubes, some buffer gets filled up and a video won't start immediately, and i have to refresh the firefox page. This also takes some time to behave like that (video not loading). F

PS done some searching: You could PM Ed Doll at Steinberg through the forum, He posted recently on the U22 mk, settings and drivers, and with some types there were also hardware issues: Steinberg forum link. PM him directly if you need help, he's a nice guy, busy though, but through the help desk it takes ages ....