AV when switching style to *2013 with a combobox

Hi,

the form is hidden behind other applications (for example an explorer window or Delphi).

After switching back to Windows 7 design the form looks like THIS

When recreating the form a normal window frame is created.

The project does not contain any code written by me. Everythis is wired up in the object inspector.

Maay be important: I am using Delphi XE2!