In version 5.21 I've tweaked things a bit to make the title of a popup a bit easier.
When a form is opened in popup mode, the "Heading" of the form is hidden, and the heading is instead moved into the "title" of the popup. This makes it easier, because there's no "extra" title to worry about. In page mode the heading appears as normal, in popup mode the heading becomes the title. This also saves a bit of space on the popup form, and makes it look a bit neater.
5.21 should be out within the next day or so.
cheers
Bruce