Sheet display issue

AppController.j

/*
 * AppController.j
 * SheetGetsStuck
 *
 * Created by You on January 23, 2011.
 * Copyright 2011, Your Company All rights reserved.
 */

@import <Foundation/CPObject.j>


@implementation AppController : CPObject
{
	var 		_feedbackSheet;
	var 		_window;
}

- (void)applicationDidFinishLaunching:(CPNotification)aNotification
{
    var theWindow = [[CPWindow alloc] initWithContentRect:CGRectMakeZero() styleMask:CPBorderlessBridgeWindowMask],
        contentView = [theWindow contentView];
	
	_window = theWindow;
	[CPMenu setMenuBarVisible:YES];
		
    var submitButton = [[CPButton alloc] initWithFrame:CGRectMake(100,100,200,24)];
    [submitButton setAutoresizingMask:CPViewMinXMargin | CPViewMaxXMargin | CPViewMinYMargin | CPViewMaxYMargin];
    [submitButton setCenter:[contentView center]];
    [submitButton setTitle:"Show Sheet"]; 
    [submitButton setTarget:self]; 
    [submitButton setAction:@selector(showFeedbackSheet:)];
	[submitButton setKeyEquivalent:CPCarriageReturnCharacter];
	[contentView addSubview:submitButton];
	
	_feedbackSheet = [[CPWindow alloc] initWithContentRect:CGRectMake(0,0,300,400) styleMask:CPDocModalWindowMask];
	var contentView = [_feedbackSheet contentView]; 		
    var cancelButton = [[CPButton alloc] initWithFrame:CGRectMake(50, 371, 120, 24)]; 
    [cancelButton setAutoresizingMask:CPViewMinXMargin | CPViewMinYMargin]; 
    [cancelButton setTitle:"Cancel"]; 
    [cancelButton setTarget:self]; 
    [cancelButton setAction:@selector(dismissSettingsSheet:)];
	[cancelButton setKeyEquivalent:CPEscapeFunctionKey];
	[contentView addSubview:cancelButton];
	
	
    [theWindow orderFront:self];
}


- (void)showFeedbackSheet:(id)sender
{
	[CPApp beginSheet:_feedbackSheet modalForWindow:_window modalDelegate:self didEndSelector:nil contextInfo:nil]; 
}

- (void)dismissSettingsSheet:(id)sender
{	
	[CPApp endSheet:_feedbackSheet];
}

@end