Can't un/install session manager

[Kent West <westk@westek.acu.edu>]

While uninstalling gdm, the process hung, and I stupidly Ctrl-C'd
it and then tried again. After that, I've been unable to uninstall
or reinstall xdm, gdm, or wdm. Here's the type errors I'm getting:

Setting up gdm (2.2.5.3-2) ...
dpkg: error processing gdm (--configure):
 subprocess post-installation script returned error exit status 10
Setting up wdm (1.20-13) ...
dpkg: error processing wdm (--configure):
 subprocess post-installation script returned error exit status 10
Setting up xdm (4.1.0-13) ...
dpkg: error processing xdm (--configure):
 subprocess post-installation script returned error exit status 10
Errors were encountered while processing:
 gdm
 wdm
 xdm
E: Sub-process /usr/bin/dpkg returned an error code (1)


I suspect it has to do with update-alternatives, but it's beyond
me to figure out how to get it fixed. Anyone have any fixes they
can toss my way?

Thanks!

Kent