Hello, Martin,  

The provided sample project and screenshots are greatly appreciated.

I have logged it in our feedback portal by making this thread public on your behalf. You can track its progress, subscribe for status changes and add your comments on the following link - feedback item.

I have also updated your Telerik points.

In order to eliminate the visual glitch in the title bar, I would recommend you to set the AllowTheming property to false. 

As to the drop down list, you can try using the DropDownList style. Thus, the editable won't be displayed. An alternative solution is to change the font size programmatically.

I hope this information helps. If you need any further assistance please don't hesitate to contact me. 

Regards,
Dess | Tech Support Engineer, Sr.
Progress Telerik