I developed a database on MS Access 2007 and it's been working fine on many machines for many years. We have now copied the front end file to a new machine that is running MS Access 2010 and I am having a problem on one of the subforms. The subform will not allow new records to be added. The front end was just copied straight accross - no changes - from a 2007 machine to a 2010 machine. All the settings appear normal. Does anyone know what may have changed in 2010 to cause this strange behaviour?