I created a new project and it works fine now. I am using XE5. The problem project had a Tableview and maybe that was interfering. I will probably use XE4 because I see that there are some issues.
There are some issues regarding creation of new forms and the TableView repainting. We have forwarded some questions about this and other issues to Embarcadero, but haven't received a response.
When I create a dialog using the code above it works correctly the first time. The next time, the dialog opens but it reacts very slowly. What is the proper code to create dialogs and release them?
Do you mean an empty form, or a form with mCL controls inside? If you are able to reproduce this with an empty form then this would be an issue in FireMonkey rather than an issue with our components.