I am in the exercise on Validation Repeating Grid, i made the fields required and proceeded to run the benefits enrollment case to test - while the flags are still there I attempt to close the window (close the case) and a modal dialog "Confirm Close"  message pops up asking me to correct the errors (note I am not hitting submit).   The options in the dialog are either save, discard or cancel  Regardless of the option I choose the error message dialog comes up.    In other words there is no way to dismiss the Confirm Close dialog box. (page 77 exercise guide middle)

Note:  I am able to resolve the issue by refreshing the entiring page in Internet Explorer