Version:            (using KDE 3.5.10)
OS:                Linux
Installed from:    Ubuntu Packages

On KDE 3.5.10 (Kubuntu 8.04) and 3.5.8 (Kubuntu 7.10):
kio_media loads on demand, HAL backend is active.

Navigating to system:/media with Konqueror or Dolphin initially works (all entries are there), but after a while nothing is shown and notifications of USB sticks or CSs/DVDs are not shown. When I navigate to system:/media, I can click on the CD icon, but get an error message (translated) "this function is only available with HAL".

Further investigation (reading source code) shows that it is a problem with kio_media's HAL backend.

While everything is working fine, executing
$ dcop kded mediamanager fullList
returns (as expected by Dolphin):
/org/freedesktop/Hal/devices/volume_uuid_2e648e91_f15c_4b78_8680_37dea36b783e
 sda2
 498G-Medium
 
 true
 /dev/sda2
 /
 ext3
 true
 
 media/hdd_mounted
 
 ---

and after a while, the same command returns:
/org/kde/mediamanager/fstab/devsda2
 sda2
 Festplatte (sda2)
 
 true
 /dev/sda2
 /
 ext3
 true
 
 media/hdd_mounted
 
 ---

(note that the first line is different)

Looking at mediamanager's source code, I'd say that HAL backend has a problem, since the second answer comes from the fstab backend.

Calling
$ dcop kded mediamanager reloadBackends

fixes the problem temporarily.

I have this problem on 100+ installations, but I cannot reproduce it on my laptop. I don't know what exactly is causing the problem. Maybe dbus is disconnecting kio_media, and kio_media is not reconnecting afterwards?
The only thing I see is cups sending very frequent add/remove printer notifications on system dbus, I don't get these notifications on my location.

For reference, dbus versions are 1.1.1 (Kubuntu 7.10) and 1.1.20 (Kubuntu 8.04).

Our temporary solution is a cron job executing dcop query,  and issuing reloadBackends when needed (mailing us active processes and last log entries). Since activating that job on a couple of workstations this morning, everything works fine... If I do get error reports, I'll post them here.

Anything else I could check?
Compiling KDE from scratch is not a possibility here, sorry.
Toni