Qt produces extra symbols under Windows using German keyboard Layout and the Numpad

Steps:
0. Use German Keyboard Layout (Windows 7 64bit)
1. Create New Qt-Widgets-App
2. Compile and run it release mode
3. When app has focus press any number on the numpad (i.e. 1)
4. Switch to any other application where you can type (Browser, Notepad, etc)
5. Now type a symbol with right alt key like \,

Expected:
The typed symbol appears
Observed:
Not only the symbol appears but also the alt-code symbol of the numpad.
This means if you pressed 1 on the numpad it would look like \☺instead of just \