Unity 4 - export terrain to Beast takes ages for upgraded project.

Duplicated my project and upgraded it to Unity 4. Everything seems to work as I would expect except “Exporting to Beast” takes 10-15 minutes for my terrain now. This wasn’t even a step I noticed before so this just added 10-15 minutes to my 1-2 minute lightmap render.

If I create a new Unity 4 project it works like it used to in 3.5 so how can I fix my upgraded project? I’ve tried reimporting all assets, deleting the terrain and creating a new one, but the terrain export takes ages no matter what.

Also, if I copy my 3.5 terrain to a new Unity 4 project it works like I would expect so something I can’t see or change is apparently broken in my upgraded project.

I have this same problem :(, but haven’t tried yet to fix it.
So it’s not just your project.

Edit: I don’t know what did it but now the export goes almost instantly.