I found an answer to the problem
The same version of bluedevil on a Toshiba laptop works with the
internal bluetooth and fails in the same way with the USB dongle.
Bluettoth external USB device I used is
Bus 002 Device 003: ID 0c10:0000
.... that has always worked flawlessly with KDE3 and with the standard
tools provided in the package bluez
pkg-kde-extras mailing list