ExtJS 3.3 target:

I can't share a project with you because it's on a private network, but here's a summary of how to reproduce:

- Add any panel style layout to a new project and set its layout to form
- Add a FieldSet with a title in the form
- Add a CompositeField to that FieldSet (which will add a text field)
- Add a SliderField to that CompositeField, creating a 2 field set laid out horizontally

At this point, the flex properties should be available for each of the fields inside the CompositeField.

Save the project then reopen the project. The flex properties for the fields inside the CompositeFields no longer exist, which causes the layout to break when exporting.