NSWindow not displayed when closeWindow command is present

Question

I need progress feedback in my app. Using an NSWindowcontroller (subclass IndicatorWindowController) that controls a Window containing an NSProgressIndicator (myBar). Everything works fine if I don't finish the procedure with [myIWC.myWindow close]. If I have this command, the window won't even show.

- (IBAction)runIndicatorWindow:(id)sender;
{
    IndicatorWindowController* myIWC = [[IndicatorWindowController alloc] initWithWindowNibName:@"ProgressWindow"];

    [myIWC showWindow:sender];

    for (double barLoop=0; barLoop<=100; barLoop++) {
        
        myIWC.myBar.doubleValue = barLoop;
        [myIWC.myBar display];

    }

    [myIWC.myWindow close];//<-When this is not commented out, nothing shows

}