I'm using virtualbox-qt 4.1.12-dfsg-2. This all worked fine in 11.10. My hardware is a 2006 Dell dimension 9200, and the USB hub is a TEAC CA-200. The user is in the vboxusers group.
The guest is win XP, and apart from the card reader not working, the obvious symptom in Device Manager is "This device cannot start. (Code 10)".
I've tried reinstalling virtualbox, and rebooting host and guest.
Any ideas anyone?