Comments not transferring to Kindle 3

i downloaded the metadata per the "edit metadata" tab.

i have "insert metadata as page at start of book" checked under common options.

i converted the book mobi to mobi, and then emailed the new conversion to my K3. the cover shows on the K3, but i cannot find the "comments" anywhere. have tried this with two different books, same result.

any ideas on what may be wrong?

i am running OS 10.7.5.

thanks