SFDC has a tendency from release-to-release of reordering the excludedStandardButtons for a CustomObject. If you are using source control populated under Vx and SFDC changes the ordering in Vx+1, your custom objects all show up as Changed in the differences viewer.

Because these are "excluded" buttons, their ordering in the XML file doesn;t matter to the end deployment and the variance should be suppressed in the difference viewer.