surprising init behavior changing levels

[Joe Smith]

When I have to drop into runlevel 3, or 1, for some maintenance thing, 
I'm in the habit of restarting the desktop using: "telinit 5; exit" so 
that I don't leave a root session running, and I don't have to switch 
back to the console to log out.

This no longer seems to work for F9. No "Starting ABC  [OK]" messages 
appeared, and prefdm was killed for spawing too fast.

There was no reason X shouldn't start, and no logged errors, so I just 
ran "telinit 3; telinit 5". This time the normal "Stopping/Starting" 
messages appeared, but prefdm was not started--no desktop.

I bailed and rebooted.

Normal level shifting (i.e. without the "exit") seems to work fine, so I 
don't think it's actually a bug, but I'd like to understand why the exit 
borks the level shift, and see if anyone has a suggestion for another 
way to re-start level 5 and log out in one shot.

<Joe