Virtualbox Win7 guest, 14.04 host, Canon camera doesn't work

Now I have a similar problem as I have with my printer also with my EOS 6D. Win7 will nag that the "device has malfunctioned" and cannot be installed. If I disconnect and reconnect, I even get an alert from Virtual Box that it cannot create the proxy file and a VERR_READ_ERROR. Of course, the camera is recognized and works fine on the host as well as on my Win8 laptop...

What's with the USB mess in Virtual Box on Ubuntu...?