This issue can occur on computers that have had Project 2007 previously installed (or possibly currently installed). After installing Project 2010, the application still refers to the old Project 2007 registry entry for the “Load summary resource assignments” checkbox status (i.e. Yes/No, True/False). The resolution is to access the registry and delete the old 2007 reference and it will then be force to reference the Project 2010 Registry location where the actual settings is being changed when the user checks oe unchecks the “Load summary resource assignments” checkbox in Project 2010. It may also be required to reinstall Project 2010 again after deleting the old 2007 reference.