[DiapDealer]

To be honest, I've never tried it with altered Amazon purchases. I almost always read Amazon's unaltered version on my Kindle and "fix" a backup version that's stored in Calibre. So synchronization always works. I only use this technique for non-amazon content.

I think you need to make sure that your altered amazon ebooks contain anything BUT the real ASIN number in it's metadata to have the best chance of success.