your normal map compression settings TC_normal map, or TC_NormalmapUncompressed?
did you flip the green channel in xnormal (sorry, I'm not experienced enough to be able to tell my looking...)
your 'swizzle co-ords' x+, y-, z+
thats all I got - hope it helps
on a side note - xnormal supports both quads and tris. so you can safely cut out triangulation from your workflow if its sole purpose is for xnormal.