The top menu button should work. And it seems to me that without a menu button, the exit button should serve that function.
The Encore defaults should usually work for you.
DVDs have a title or top menu, which will take the user to the menu specified for title remote. Timelines have a menu property, which takes you to the menu specified for the timeline (menu remote). The two should not be confused. So check that neither of these has been set to something odd.
Go to the Flowchart and select the Disc icon. Then look at the Properties panel. Set the title remote as you wish - where will the user go when they push the top menu button.
Also select any timeline, and in the properties panel under "menu remote" set to the desired menu. I think the default is "last menu" and works fine for me.
Thank you I will give this a try- really grateful of your help