The problem is with KDE 4.* development, not SL. Anyway, you can get it working in the KDE edition of SL 4.1 and SL 4.2 by installing kdebluetooth4 from the KDE testing repository. See the thread Bluetooth problem still present... [Solved]
for the instructions. For the GNOME edition of SL use Blueman.
If you use the SL Forums Search facility you'll also find other pertinent information on Bluetooth.