On a couple workstations we noticed a conflict between PrimalScript Enterprise and the Powershell Community Extensions (PSCX). PrimalScript would throw an error and terminate when opening a file with a .ps1 extension.
I posted a follow-up on the Codeplex discussion board. Oisin quickly responded with a fix.
Look for the line in your Pscx installed $profile that says:
Start-TabExpansion and comment it out with a #. This will workaround the problem.
Bingo! Now I can continue using PSCX (if you are not, you need to take a look) with PrimalScript. Thanks Oisin!