Comment 6 for bug 286273

The problem was a known problem on Dell Ubuntu systems upgrading kernels - see http://linux.dell.com/wiki/index.php/Ubuntu_8.04#Known_Issues

After rebooting with the kernel modules fixed up, the volume control program no longer crashes.

I'm not sure if you still want to debug this... it seemed to happen when there were no devices which I guess is a good corner case