I encountered what appeared to be a SP2010 bug, but I can't find any other information from others who have experienced it.
We had a site with a SharePoint list with a Title field and a Rating field (and many other fields). If the Title contained an ampersand, then the Rating would not save. Neither would the user see their own rating as saved if they re-opened, nor would it be added to the calculated average rating.
When we changed the titles to remove the ampersand, the rating feature began to work again.
Is this a known bug?