I'm not sure if in the process of updating to SW '11, I changed some of my settings, but back in SW '10, if I were to add a mate that caused an error based on other previous mates...all mates in question would turn red in the feature tree. This made it easy to pin point problems and possible to delete previous mates that may have previously been for general positioning to get rid of any errors. In SW '11 if I add a mate that interferes with other mates it is the only thing to display an error (turn red) in the feature tree.
Also some assemblies display (+), (?), and (-). I know (+) is overdefined and (-) is under-defined, but often assemblies that are (+) overdefined will display no errors (or I suppose turn red to show there is an error). Is there a setting I can change to make the feature tree function like I am used to?