today, i bught Bus 003 Device 018: ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode)
and have following problem, device working few seconds after connecting, than return timeout on any action, for example:
hciconfig hci0 up
Can't init device hci0: Connection timed out (110)

and in dmesg:

[ 7883.363380] hci_cmd_task: hci0 command tx timeout

i using following software:
uname -a
Linux evil 2.6.35-zen3 #11 ZEN SMP PREEMPT Sat Oct 2 16:07:09 EEST 2010 x86_64 Intel(R) Core(TM)2 Duo CPU E6750 @ 2.66GHz GenuineIntel GNU/Linux
net-wireless/bluez-4.71 ((alsa) (attrib) (caps) (consolekit) (cups) (-debug) (gstreamer) (lib32) (-maemo6) (mcap) (-old-daemons) (-pcmcia) (pnat) (-test-programs) (usb))

distribution is gentoo

P.S. i found kernel bug's on bugtracker from ubuntu, debian and red hat distro, but non of proposed solutions are works ...

i will provide debug info later

i made some tests with debug kernel, hereis dmesg http://pastebin.com/bMWStMwL , but i do not see useful info (, now i will check device under windows on kvm