Whenever I load my ISE project that has my EDK project as a submodule, ISE reimplements my EDK project even though no changes have been made. Why does this occur?
ISE looks for a time stamp difference on the EDK .xmp project file to determine whether the EDK project should be reimplemented. XPS updates the .xmp file's time stamp to the current time every time XPS loads the project.
Currently, there is no way to work around this issue. This problem will be fixed in the next EDK service pack.