A developer's life is filled with PEBKAC errors. More importantly, anticipating them. For the one guy reading this who doesn't know what a PEBKAC error is, it stands for "problem exists between keyboard and chair."
When you're building an application, one of the things you're always doing is looking for ways users can screw up the input. So you provide error handling to anticipate this. One such issue is when a user makes a change without saving it when they're in an .A5W page.
Now there's a solution. You can write custom code to prevent the Tabbed UI pane from closing if the .A5W page is dirty. It will display an alert asking the user to either save the changes or abandon them. The code works by setting an arbitrarily named property of the Tabbed UI object called "gridIsDirty." You can see step by step how this is done in the videos below. I think it's safe to say that this will prevent a few PEBKAC errors.