I have a Logitech 350 USB Headset (and had another Logitech USB headset) and have had the same problem since 10.4.2. and including 10.4.3.:
If I put my computer to sleep and awaken it, the USB audio will not work...it will be silent. I can reenable it by opening "Audio MIDI Setup", selecting the mute option for the headset, then unmuting it. It works then, but the audio levels are low, so I then drag the left and right volume slider within "Audio MIDI Setup" to restore the volume levels. Annoying.
Does anyone lese experience this? I have to assume the answer is "yes" since this is a driverless device (e.g. the OS provides the driver). Oh, and Detour no longer works with 10.4.3. Grrrrr.
Thanks for any advice.