Further USB Sound card issues - Freezing host.

Hi Folk.

We are having further issues that I'd appreciate some thoughts on.

Have have had random issues attaching a certain model of USB sound card to a guest machine.  Occasionally when we do this the host system completely freezes it seems at the point where it is detatching the USB sound card from the host and assigning it to the guest.

We have just got a second type of USB sound card to try, being a newer model, but this one is freezing every single time we attach it to a guest at the point where it seems to be grabbing it.  The last line of the log file of the guest is: husb "grabbed usb device" 1.4 or along those lines, then the host freezes (the pixels get a bit 'washed out' at this point too, and I have to hard kill the machine to restart it.

Can someone please point me in the right direction?

We have upgraded qemu to 1.2, and virt-manager 0.9.4, which have helped with a previous problem of allocating USB sound cards to individual guests on a permenant basis.

Thanks,
Owen.