We've just added a new site feature -- the ability to see who rated you, including a link to the rater's gallery page, when he or she rated you, and what rating they gave your work.
To learn who rated you just login to your account, click the 'my uploads' tab, and the rating information is listed next to each of your uploads.
Since we just initiated the program today (Friday, November 12th 2010) we are not displaying previous star ratings, just the rater's username/link, and when he or she rated your upload.
We were not previously recording the rating value for each person, just the person who rated and when that person rated. Moving forward you'll see star ratings next to each entry instead of the 'unknown' that you'll see when you look now at previous rating info.
We were asked by a number of users for this enhancement, and we listened. Thank you!
Enjoy!