Device notifier on fedora 12 + k12linux

[J Afiune]

Hi there,
I am preparing a Fedora 12 + K12linux + KDE server and found a problem
at the K12linux workstations:
The Device Notifier is not working as it shoud.
All settings matchs install instructions.
At server's console it works fine.
When I insert a DVD at wokstation's drive, /dev/disk/by-label and
/dev/disk/by-path shows it, but the device notifier doesn't.
The same happens on usb connections.
I'd appreciate some help to fix it.
Thanks a lot.