i have an application which have a main form and a sub form.
if the application is started, main form and sub form will be displayed, the sub form is displayed over the main form.
it works great on dual monitor of mine and other customer's.
but one customer has problem with his dual monitor. When he starts the application, the sub form is hiden behind the main form. Only by using "Alt + Tab" can this sub form be invoked and displayed again.