If you do not undo the changes then that would be true.  When you return you need to either undo or save the changes if you want the state of the BO to change back to "Idle"

The problem I am having is that I am calling a form childform in Edit mode and canceling it. When I return to te parent form, the maintenacetoolstrip Save button is enabled only. The edititing state is returning from the childform is still in add mode?  

When you handle the Before events, you can prevent the action from happening.  For example:

don't know, if this is possible the easy way, but you can catch the appropriate events much more precisely on the BO's, which gives you more control, e.g. BeforeSave, AfterSave and so on.

HTH, Ralph