How can I manipulate the Ultratoolbarsmanager's ribbon tab?

here what I want to do..

I have a Ultratoolbarmanager in a mdiparent and mdichild window.

I want the several buttons in the ribbon tab body to be visible when opengradebook child window opens and make them invisible again when the opengradebook window closes.

The ribbon tabs in the mdichild and mdiparent have the same key name of Home and a caption of Gradebook.

But when I open the opengradebook form. another ribbon tab named Home appends in the tab list.

Form before calling the opengradebook form

Form after calling opengradebook