Bug#570478: Also experienced

[Filipus Klutiero <chealer@gmail.com>]

I was hit by something similar after upgrading kdm from 4.8.4-4 to 
4.8.4-5, which changes the default kdm configuration. I decided to take 
the maintainer's version of the script and then kdm wouldn't start 
anymore. However, the Login Manager configuration tool still let me 
configure kdm.

/etc/init.d/kdm is responsible for substituting 
@@@ToBeReplacedByDesktopBase@@@ when kdm is started, at line 86:
> sed -i "s|@@@ToBeReplacedByDesktopBase@@@|$DEFAULT_KDM_THEME|" ${KDMCFG}
This failed because my kdmrc was in /var/run/kdm/kdmrc/kdmrc rather than 
in /var/run/kdm/kdmrc. I was unable to figure out why (even after 
reading upgrade scripts) but /var/run/kdm/ was a directory which 
contained a kdmrc/ subdirectory.
Deleting /var/run/kdm/kdmrc/ works around.