Excel print dialog not attached to windows forms app

Question

When I show the excel print dialog it pops up correctly but if the app loses focus and the user refocuses it the excel dialog will not show up with the win form app.

Im showing the print dialog with the following code

Dialog print = xlApp.Dialogs[Microsoft.Office.Interop.Excel.XlBuiltInDialog.xlDialogPrint];
print.Show();