Tiling UVs show black border across faces in 2048x1024 texture?

[FiftyTifty]

For some reason, 3DS Max is showing a vertical black border between the edges of each face. This isn't present in RizomUV:

In 3DS Max after using UVW XForm to set U Tile to 0.5View in RizomUV before export

I suspect this is because of hacing to use the UVW Xform modifier to display the UVs properly with a rectangle texture map. Unfortunately that is the largest supported resolution by the game engine, so I can't use different dimensions. Is there a better way to go about this?