Darn it. You're the second person to get that error.

After all of our... er... five minutes of testing. On two computers.

I believe it's something to do with a missing DLL (despite the error message). We'll have a look at it later today and get an updated version out. In the meantime, someone managed to get it to work by installing .NET 2.0.

See, kids -- this is what happens when you don't design your algorithms and document your code :)