hmm, you know, I see I have a similar trouble, (using Carrara 2.1 here) and the way I just got around it was by opening V3 in uvmapper first, and saving V3 out again, unchanged. Then import the resaved mesh into Carrara (as facet mesh, a single polymesh, needed for morph targets, you know the drill but stating it here for others that may not) and she saved just fine. :)