When running EMWProf script through GPO it may interrupt unexpectedly. When analyzing log files from different computers there are no errors logged and there is no consistency or pattern in a moment when it quits.
This is by design of Microsoft GPO Scripts extension architecture.
GPO Scripts extension system has a maximum wait time for Group Policy scripts execution. It can be configured in every particular GPO using Group Policy Object Editor Console, under Computer Configuration | Administrative Templates | System | Scripts. When reaching this time limit all the login scripts are interrupted.
Refer to the following Microsoft TechNet article: What Is Scripts Extension? - http://technet2.microsoft.com/WindowsServer/en/Library/32571e90-831b-4e88-8aa7-d6999f291c6d1033.mspx?mfr=true