LINQPad: "BadImageFormatException" when using (.NET4) VS2010 assemblies?

Using LINQPad I am trying to test a few snippets with my own C # Objects, which are written in .NET 4.0 (Beta 1) using VS2010 B1. When I try to use it, I get the following message in LINQPad:

BadImageFormatException: Could not load file or assembly file: /// C: ... \ XX.dll or one of its dependencies. This assembly was built with a runtime newer than the currently loaded runtime and cannot be loaded.

In this post, one of the LINQPad authors mentions that ".. there is already a Framework 4.0 build ..". Does anyone know where he is, or how to get him?

I also searched for the manifest file for LINQPad.exe, as I know there is a way to extend the .NET 4.0 support by adding this as a supported version to the manifest file. I did this once, but now I can't seem to figure out how to do it! Does anyone know the link? Not to mention, I don't know if this will work for LINQPad and if the manifest file is embedded (since I can't see it).