Embedded Excel chart in MS Acess

Hello,

I've got 4 embedded excel chart on my Access form. When I have an excel application already running and then open the form, 4 empty workbooks are created in my application 'Book 1','Book 2','Book 3','Book 4' and when I close the form, these workbooks still exists. As the user can browse through several forms, the number of empty workbooks are adding up so they have to close it manually. How can I avoid this?

When no excel application is running and open the form, I see indeed in taskmanager that Access opens a excel application in background and when I close the form, the application gets closed too, so no problem there. Its only when the user has already an existing excel application running

*bump* no one?