Several developers have been complaining on Android Market forum that a decent amount of their app ratings are missing from the Android Market. Many of the developers have lost more than half of the ratings, which obviously can effect the overall rating, especially if they lost many 5 star ratings.

Google has already responded to this issue, stating that they ‘have identified the cause of this issue and are working to resolve it.’ They also have added this issue to their Known Issues page.

Hopefully this issue will be resolved quickly!