Using "Qt 5.1.0 for Windows 32-bit (MinGW 4.8, OpenGL, 666 MB)", some javascript applications fail to work when compiled in Release mode, but work in Debug Mode. No error appears in the javascript console.
This affects (to my knowledge) angular.js applications.

Enclosed, a minimal project (one single cpp file) that reproduces the problem. I added the file main.cpp to the attachements.

To reproduce:

• Open the enclosed project, or create a project and add the main.cpp file attached.
• Compile and run in Debug mode: "Hello, world!" appears (it works)
• Compile and run in Release mode: "Hello, {{ who }}!" appears (it didn't work)