I had a problem with a non-tiling texture (the green pixels at the top):
I thought setting the texture to non-repeating would fix it, but Codex generates UVs from -1 to 0 (instead of 0 to 1). So I added a 1.0 in front of every minus in the lines 60 to 90 in lb_global.gd, and that helped, but I didn't test it thoroughly.