virtualbox.org

A Windows 7 SP1 64-bit host;
A Windows 7 SP1 64-bit Guest;
VBox 4.2.10 r84104 + Guest Additions 4.2.10; full USB support;
Logitech h390 USB Headset (w/microphone)
Windows host and guest both install drivers for Headset.
Attach USB Headset device to guest using Devices menu on VM.

On guest, launch Audacity 2.0.3; normal start-up.
Set speakers to Logitech Headset; Normal so far.
Set Microphone to Logitech Headset; GUEST HANGS!
Has to be aborted and host has to be rebooted.

On Windows 7 SP1 64-bit (no VBox) Logitech Headset works as expected.

On Windows XP SP3 32-bit (no VBox) Logitech Headset works as expected.
Audacity 2.0.3 works as expected.

Is there a workaround or a fix for this?

Thanks

There are known issues with anything sound & USB related.
If you search on the bugtracker you'll see a ticket for it.