Qt 4.8: Text on QPushButton becomes selected when window is shown

I have a simple QPushButton being initialized with some very simple code:

QWidget window;
// ...

QPushButton button("New Project", &window);
// setGeometry... setStyleSheet...
button.show();

But when I launch the application, it appears as if the text in the button is selected like this:

There is nothing related to a bluish tint in the stylesheet, and when I focus on another window on the screen it's normal again:

It doesn't occur on OS X, but with my Linux install it happens. I presume it's some sort of issue regarding which window is in focus selecting text?

Thanks in advance for any help. :-)