This revision demonstrates the bug:
http://code.reloado.com/upokav3/2/edit#preview1. View the tab with the datagrid, observe it is correct
2. Switch to the first tab
3. Close dialog
4. Open dialog
5. View the tab with the datagrid, observe it is a blank box.
The changes to this revision is the call to the loadData and setting the datagrid to a specific size.