I probably found where is the mistake. I use qemu 0.9.0 of debian unstable.
With the tree version: if I try to add the BB 004 or another USB bluetooth dongle the cli say:
"Could not add UBS device 'host....'
and in the logs
"usb_host: only one interface supported"
This happen because qemu does not support usb multiple interface... (this is what i understood) so I patched with [Qemu-devel] USB Multiple interface devices
With this patch i have the result reported in my opening thread and i have the SAME effect with the usb bluetooth dongle (after 10 hours of driver recognition no ending...)
So I think that is not a BB throuble but a USB - QEMU problem.