I had some trouble receiving files via KBluetooth 0.4,
Related to KDE 4.3.2, Ubuntu 9.10

Basically, simple fix:
1.
Code:
sudo apt-get install obexpushd
(ie, install the obexpushd package)

The bug:
- I think there's something wrong with the package obex-data-server.

That said, KBluetooth should send files (just might not receive files without obexpushd)