User switching fails

[Michael Knepher]

After having an attempt to upgrade my jaunty desktop to karmic fail and
leaving me unable to boot, I went ahead and did a clean install (I
have /home on a separate partition). The install went without issue, and
I booted and logged into my account. 

After some housecleaning with re-installing apps and such, I opened
System->Administration->Users and Groups to restore the accounts for my
wife and kids. When I tried adding my wife's account, I got a message
saying the home folder already existed and the account couldn't be
created using that folder. Rather than juggle folder names, I closed the
Users and Groups app, opened a terminal, and added the accounts and set
the passwords using useradd and passwd. I added each account in the
order in which they had originally been created, so the user account
UIDs and the UIDs of the home accounts were the same.

Logging into each account from GDM works perfectly. Whenever I try to
use the session applet to switch users, however, I get the unlock dialog
for the current account. I can get back to the account by entering the
password, but nothing else. Hitting the "Switch User" button on the
unlock dialog just brings up a screensaver which hides the unlock
dialog. It's focused for input (typing the password and hitting enter
returns me to the desktop), but only shows up if I use ctrl+alt+fn keys
to go to another vt and back. 

So I'm stuck in a situation where it is impossible to switch user
accounts without completely logging out of the current user session. My
laptop behaves as expected, with Switch User... taking me to the gdm
login screen, even though I have only one user account on the system. 

Does anyone have any idea where I might look to try and fix this? I
don't know if this is a problem with gdm, the session applet or the user
accounts.

Michael