roscoepico - 3:31 pm on Jun 30, 2010 (gmt 0)
Ensure that the store names are consistent across all shopping engines. Google crawls these reviews and needs to be able to match store names. Sometimes something simple like letters capitalized can cause an issue. Also, reviews/ratings disappear from Google Products all the time. Chances are if nothing has changes and the store names are consistent, those reviews will return.