A strange sound bug seems to appear as reported on facebook...:
"Some times, after starting USDX, there is no sound at all, but if I then restart USDX using admninistrative mode, it usually works without any problems.
The strangest thing is, that I have disabled UAC, so I don´t see what the administrative mode changes.
This is the only bug which happend to me so far, but it happens frequentlly. This bug appears only on 1.1 if I use the challenge mode I haven't had any bug at all yet."

... and forum:
http://ultrastardeluxe.xtremeweb-hosting.net/viewtopic.php?f=17&t=1091