It looks like this is a pageframe UI refresh issue. I've added a third frame to the cBizobjMaintenanceForm, which comes with two frames by default. When Page 3 is first activated, the edit regions work just fine. As soon as I change the record pointer on the page's bizobj and refresh the edit regions, they're frozen. In fact, as soon as I click in the grid that's tied to the page's bizobj, the edit regions get locked so the scrollbars don't work.

It looks like there's a formlock or UIEnable that's not getting run after the initial activate or after the grid click. I tried doing a Page.Activate and a Page.Refresh but that doesn't help.