OK, sorry about the confusion.
That definitely seems to imply that the ASIN is not being embedded in the file you tried using X-Ray Builder on.
And since I know Quality Check works...
Ephemerality's suggestion is a good train of thought to follow.
You could use KindleUnpack (calibre plugin) to open the in-library MOBI and check the content.opf to see what the ASIN is.
Or calibre's command-line tool
Code:
ebook-meta "C:\path\to\Calibre Library\path\to\ebook.mobi"
Look at the Identifiers value for "mobi-asin"