Qt 4.3.0 clipping problem?

[macbeth]

Hello everyone!

I compiled Qt 4.3.0 when it was released and my application behaves quite weird...(it worked using Qt 4.2.3) I am not sure, but maybe I've found a bug in clipping, but I'd rather ask here first...

so, the code is rather simple:

int main(int argc, char *argv[]){
        QApplication app(argc, argv);
        int height = 500;
        int width = 600;
        QPixmap myPixmap(width, height);
        QPainter myPainter(&myPixmap);
        myPainter.translate(0,height);
        //make the coordinate system look like this:
        // -y   ^
        //      |
        //      |
        //      |
        //      |
        //      ----------->
        //    0,0       +x
        QRectF myRect( 100.001, -100, width-200, -(height-200) );    //**here lies the problem, I guess
        myPainter.setClipRect(myRect, Qt::ReplaceClip);
        myPainter.fillRect(0, 0, width, -height, Qt::cyan);
        myPainter.setClipRect(myRect, Qt::NoClip);
        myPixmap.save("out.png", "PNG");
        return 0;
}

int main(int argc, char *argv[]){
        QApplication app(argc, argv);
        int height = 500;
        int width = 600;
        QPixmap myPixmap(width, height);
        QPainter myPainter(&myPixmap);
        myPainter.translate(0,height);
        //make the coordinate system look like this:
        // -y   ^
        //      |
        //      |
        //      |
        //      |
        //      ----------->
        //    0,0       +x
        QRectF myRect( 100.001, -100, width-200, -(height-200) );    //**here lies the problem, I guess
        myPainter.setClipRect(myRect, Qt::ReplaceClip);
        myPainter.fillRect(0, 0, width, -height, Qt::cyan);
        myPainter.setClipRect(myRect, Qt::NoClip);
        myPixmap.save("out.png", "PNG");
        return 0;
}

To copy to clipboard, switch view to plain text mode 

using this code I get an image with a cyan rectangle in the middle, as expected.
However, if I change that one marked line to:

QRectF myRect( 100, -100, width-200, -(height-200) );

QRectF myRect( 100, -100, width-200, -(height-200) );

To copy to clipboard, switch view to plain text mode 

the image is entirely black...

Am I doing something wrong, or do you find it weird, too?

Thanks for answer...