well this is strange, but it seems it conflicts wth some other device connected to the same usb hub...
if bluetooth dongle is first device which i connect do hub, everything works as it should (more or less
)...
*EDIT*
after a bit of connecting & disconnecting, i have a feeling that conflicting device is exteranl dvd-rw drive, i read something about it somewhere
that bluetooth module needs to be loaded before usbfs or something like that...
hope it helps also somebody else