我正在获取无法设置可见性或调用Show，ShowDialog Exception

I'm using WAF (Wpf Application Framework) to create a dialog as shown in the ModelView sample application. I am trying to put up a simple AboutBox by mirroring the code for putting up the CreateEmailAccountWizard dialog box. My About box shows up fine the first time, but when I call it again from the menu, it gives me the following exception:I'm using WAF (Wpf Application Framework) to cr