When i installed bluez the bluetooth dongle i used is the one made by TDK... now when i tried using a different dongle, a Billionton class B, it seems linux cannot startup the bluetooth system...

 

i.e.

"hciconfig hci0 up"

 

linux outputs a messaging saying the device is not present or not connected.... when i switch back to the TDK dongle, then it was ok...