But it is seamless. You're looking at the same spot in all three images up there - the seam only appears when I have the diffuse and alpha together - as you can see in the alpha in the middle, it is seamless.
Those are all viewport screen grabs. The seam that shows up in the middle of the "Together" shot that has 3dsmax displaying my Diffuse and Alpha together has a seam in it. The seam disappears if I have it show just one map. Does this make it more obvious as to what you're looking at? This is driving me nuts