QApplication and Bullet3 Simulation

Hi everyone,

I have an existing QT project and need to include a Simulation, which I decided to use Bullet3 for. I am using the b3RobotSimulatior API. After some workaround I am at the current point:
I have a class A that creates a simulation and 'hides' all the bullet3 stuff at one place. I am basically parsing a xml file to create a robot. Another class B, inheriting from QThread, creates an instance of class A and is an interface within my QT project. Even though that is not my final goal, right now class B is initiated in the main() and started from there, while the main just idles.
When nothing else is created the simulation works as expected. However as soon as I include QApplication and create an application before the initialization of class B in my main() the parsing of the xml file seems to fail. All the floating values in the xml, as mass and size of the robot, are casted to an integer. I compile with qmake, while all Bullet3 code is precompiled and included as shared library. The parser is part of bullet3 and precompiled in a shared library. It uses some sourcefiles of tinyxml as basis.
To make the simulation fail I do not change anything, but adding the line before initialization of class B:

Code:

---

//QApplication a(argc, argv);
 
ClassB b;
b.start();

---

Does anyone had the problem before or has an idea where to look and why QApplication has an impact on the parsing.

Thanks,
Chris