I've gone through my code, but doubt it is due to spacing of the objects themselves. They're 4.0,4.0 sized planes and they are spaced 4.0 units, so this works in terms of placement.
I have also checked the texture and the pixel line is actually outside of the texture (it's a larger texture where I'm using UVoffset information to show the correct texture, like how someone used it for animations on this forum too.).
horiPos = Mod( planeAni, numberOfFramesHori)
vertPos = Trunc( planeAni/numberOfFramesHori)
SetObjectMeshUVOffset( fogmap[q,w], 1, 0, horiPos, vertPos )
Any ideas what I should be looking for? I do remember the manual mentioning something about a wrapping issue or 1 pixel texture issue, but can't find it anymore.