It took me several months of experimenting with a small subset of my music collection to find the right combination to get things to work.
After that, I fixed my entire collection (+4,000 songs) in a few minutes with MP3tag (
Mp3tag - the universal Tag Editor (ID3v2, MP4, OGG, FLAC, ...)) and FastStone Photo Resizer (
FastStone Photo Resizer - Powerful Image Converter/Resizer) (both are free/donation ware software).
But yea. MS has screwed the pooch with XBM. I know there are those who yell, Fire the XBM programmers, and rehire the Zune programmers. You know what, after doing what I had to do to get things to work on my own, I agree. The should have taken the Zune code and just done a search for 'Zune' and replaced with 'Xbox music' and called it a day.