What is causing this strange shadow on my floor seams?

I have made a static mesh floor in Blender and imported it into UE4 everything worked perfectly until I lined the flooring up to fit and realised that they have a strange shadow on the corners of them every time lighting is generated any idea what might be causing this? Here is an example:


Here is a video that rendered terribly however here it is anyway:

http://screencast.com/t/JdBHqfYd

And here is the FBX:

http://www.sendspace.com/file/fnltb7

Thanks!!!

Hi Nickmadd -

Your second UV channel for Lightmaps has no padding between your UV islands, so you are getting a shadow bleed between two island sets.

Thank You

Eric Ketchum