I knew it wouldn't be that easy.

I just received this from Amazon:

To confirm your rights to distribute the book(s) listed above, please provide any documentation or other evidence that proves you have retained rights for these book(s). Alternatively, you may have the rights holders contact us directly with confirmation that you have retained rights.

Exactly how do I prove I DIDN'T give up the rights to my book that they've happily been selling for me for the last 2 years? Give me a break.