This turned out to be an error in the creation of the client. It was cleared up be recreating the client from scratch and applying the same bundles. Please ignore the message. I am at the end of a project to upgrade a network 22.214.171.124 installation to a 7.5.3 installation. I have reworked all of the forms and scripts and everything seems ready to roll out except on the middle pane of the contacts and opportunities, when I choose to bring the contact tab to the middle pane in the opportunities it will not display and actually disappears from the displayed tabs and I cannot get it back into the tab list unless open the user in admin and re-enter all of the tabs back to visible.
What is strange is even though the "Always On" is checked the "visible" for the tab goes away in the Edit tab list of the user settings when in the client the user selects the tab to display in the center pane. Is this something that is broken in 7.5.3, or just with my install?