With the necessary modules loaded (apart from USB-support bluez.o, l2cap.o, hci_usb.o, rfcomm.o) everything works perfectly well.
If you use usbmgr instead of hotplug add the following line to /etc/usbmgr/usbmgr.conf:

vendor 0xa12 product 0x1 module bluez, l2cap, hci_usb, rfcomm

For details how to setup Bluetooth with a mobile phone follow the link to my page about bluetooth and mobile phones.