DLL build issues with Unity 3

I'm building a game which makes use of a program outside of Unity called ReacTIVision, which is used to track markers with a camera. The game works fine inside of Unity's editor, but whenever I try to build, it fails and I get several errors - which I'm pretty sure are all related.

The error is related to the Uniducial code I found online, which adds ReacTIVision support to Unity. This was designed for a version of Unity 2, so I assume that there has since been some change to the code which is causing the error. However, the coding involved is a bit beyond me, so I wouldn't even know where to start looking. Here is the first error:

ArgumentException: The Assembly UnityEditor is referenced by UniducialLibrary. But the dll is not allowed to be included or could not be found.

and the second:

Error building Player: Extracting referenced dlls failed.
UnityEditor.HostView:OnGUI()

and the final one:

Exception: Error building Player: Extracting referenced dlls failed.

Someone previously suggested changing the build settings to use NET 2.0 instead of NET 2.0 Subset, but that didn't work. I should also point out that I'm building for PC Standalone, and I'm currently using the Unity Pro Demo.

Please help, my uni deadline is fast approaching and I can't build a copy of my game to hand in!

Thanks!