After trying to edit my outfit and shape with no success I clicked the "Undo" button and my avatar became visible. The textures all also were restored to their proper appearance.
When I try to edit my avatar's body or clothing the panels which show the choices (e.g. eybrows) just appear as random colored pixels, much like a sculpty being displayed as an image. I'm running the latest version of the viewer under Mac OS X 10.6