Could be a few things. Best guess is that the uv positions of the seam are on a UV border, ie close to 0 or 1 in uv space, and are being translated as over the border on import to the editor and so you are getting a few texels wrapping from the other side of the texture.
Why not just weld all the geometry elements together at the seams in Maya? That wont harm the UV shells, and assuming the shell borders are the same as the geometry borders you could simply export from zbrush based on uv-polgroups to get the original breaks if need be.