I've never used Mudbox, but I create morphs for Genesis in Blender. What do you mean by "warp"? I know that if you don't maintain vertex order on export (from Blender to DAZ, in my case) Genesis will "explode" when the morph is dialled. The settings I use to export are to check "Objects as OBJ Objects", "Keep Vertex Order" and "Polygroups" (and the last two settings also when importing). I don't know what the export settings are for Mudbox, but perhaps it's something like that.