there might have some reasons
- you actually got overlapping UVs
- your UV margins are unsifficient for non adjacent tris
- you use a diffuse UV layer ( wich allows overlapping ) instead of your lightmap UV ( wich don’t )
I use to have 2 UVs for unity the 1st one for diffuse/spec/normal/displ/etc… and the second one for lightmapping/dirtmapping
And yes this IS the BGE and UPBGE ( wich is not part of blender and therefore has nothing to do over here just as U3D/UDK/CRY don’t ) reserved forum. You should post in the global game engine forum wich don’t restric the talk to BGE, preventing dog-guards to piss you off with useless posts
happy Blending and Unitying !