Can not start some Administration applications

[Craig Hagerman]

I have a strange problem. I did a fresh install of Ubuntu Dapper Drake
(32 bit) yesterday and spent much of today setting it up. Now, some of
the Administration options (System > Administration) will not start
up. For example: Device Manager, Login Window, Users & Groups - when I
click on them there is a notification in the panel saying "Starting
Administration Application" and the cursor changes to a rotating ball
.... and then after a minute or so it all goes away (without the app
starting). Some other (less significant) applications start up as
normal (e.g. System Monitor)

I have absolutely no idea what is going on here or how to fix the
problem. I can't even find any way to start those apps from the
command line. (I can log in as root and do everything normally from
the terminal.)

After I installed Ubuntu and started to set it up I changed my user ID
and group ID from 1000 to 501 (so that I log in via NFS from my mac
powerbook where I have that UID/GID). This is the only thing I did
which might account for the above behaviour, but I did do a find and
changed all of my files reflect the new ownership, I made sure that
/etc/passwd was changed correctly etc. I also created two more users
and gave them administrative privilages (given UID/GID of 1000 and
1001 by default), and neither of those users could open the
Administration Applications either.

Odd huh? I am puzzled and wonder what I should do at this point. Any ideas?

Craig