I have a TeamCity 7 Build Configuration which is pretty much only an invocation of a .ps1 script using various TeamCity Parameters.
I was hoping that mig
There is an known bug in TeamCity that causes the behavior that the original poster noticed.
It is easy to work around, however.
At the end of your PowerShell script, add output indicating that the end of the script has been reached:
Echo "Packaging complete (end of script reached)"
Then, set up a new Build Failure Condition on your build to fail if the text you are echoing is NOT present in the output.