I have the same issue, and can agree that it is really frustrating (have tried 100x variations, without success- as mentioned above).
- two additional pieces of information:
1. changing and re-adding the Full Body Alpha does not work (alphas in general, I have tried various, work to hide the new skin, but not the old)
2. when I click to modify shape. my avatar looks "correct" and "normal" (even to screen shot), however to others looks like the problem (BOM skin showing through, even upon new region/re-teleporting- - re-logging the appearance to my viewer also reverts to the problem)
my 2 cents on this one... lets see if there is a better answer out there!