Using Callouts on a Visio form

[j1023walk]

I am trying to add a callout object on a Visio form that was created from background page with a border frame and functional bands.  Whenever I add the callout object, I can easily connect it to a shape on the form, except when the callout is near the middle of the form.  When moving the callout object near the middle of the form, the connector tail suddenly attaches to the frame around the edge of the form and the form edge turns red.  Very bizzare action.  Does anyone know why this takes place and how to correct it?  Thanks.