I've read the whole thread about running PowerShell under .NET 4.0, including the warnings about what happens when using the registry keys to make the scripts run under that framework.
So far, I only get the desired result with the registry keys. Is anyone aware of a way to make this work without changing the registry keys? When I checked PowerGUI's discussion boards, even they pointed to the stackoverflow thread. Has anyone come up with something better since April 2010?