[dnanian]

Is "TEST.txt" something that's on the source? If not...well, *something* is creating it, and it's not us.

I can't see how any normal Spotlight or maintenance script could prevent logging out or restart, given those daemons would be killed normally. I really wouldn't hard power off, though. Have you tried running

sudo shutdown -r now

in Terminal when you can't log out? Have you looked at the Activity Monitor to see what might not be actually exiting?