Familiar experiece, unfortunately. Carrara deals with normals on an entire polymesh at a time. So if one spot is reversed, attempts to fix it will warp everything else. I have two strategies for dealing with them. First, I use the "detach polygons" command frequently. I've found Carrara can also do nasty things, included lock-ups and crashes, if you do certain manipulations on a selection that happens to include a stray poly from elsewhere. "detach polygons" tends to clear that up. The other is avoiding n-gons. I am not entirely sure Carrara has problems with them, but I seem to have reversed normals less often on models that include only quads or tris. I'd suggest you get out of Carrara on this one; export the model, maybe run it through UVmapper and resave it, then re-import to a fresh file. Sometimes Carrara just gets a funny idea about a mesh and this is the sure way of cleaning that memory. That said, I wish the reversed normals were more obvious (like the arrow display of several other applications, perhaps?) Sometimes I don't notice them until I've imported into Poser.