Well, depending on your definition of glitchy, I may be able to help.
I had a problem with some skins and texture mix-mapping. This was corrected easily by downloading the latest version of Image Extractor 2 and re-converting my .tga's to .blp's.
If this isn't the case, please post a copy of your skin (or PM it to me) and I'll try to see what the problem is.