I've installed openSUSE 11.2 and Xen 3.4.1 for dom0, and create a Windows XP domU virtual machine by YaST Virtual Machine Manager. Initially, no virtual sound card is attached in this domU, and the virtualized Window XP works fine. But after adding a sound card (i.e. ac97, or sb16), and starting this domU, a dialog pops up with the following error message:
Error starting domain: POST operation failed: xend_post: error from xen daemon: (xend.err 'Domain unable to be unpaused: an integer is required')
And after removing the virtual sound card, it works fine again.

View xen's log (/usr/log/xen/qemu-dm-windowsxp.log.???), I've found an error message:

/usr/lib/xen/bin/qemu-dm: invalid option -- '-soundhw'

It seems that qemu-dm cannot recognize the option for assigning sound hardware: '-soundhw'

Does anyone points the direction that how can I solve this problem without much technical operations (i.e. patch and re-compile Xen). Thanks a lot.