I think you've solved my quandary Quest - it is an output channel rather than me thinking it was going staight to the bump. As in, those 3 windows in pic editor equated to the 3 windows in mat editor - now I see why they don't - thanks.
Direct painting on the oject is far more satisfying I'm in no doubt about that and I'm thinking it is possible to put lettering and many other effects on via metasequoia.