After a whole day, reading stuff on stackoverflow, blogs and looking at sources... well... here is the story:

I wrote an app. It shows 2 images with a small flicker between them. To avoid tearing I used qgl with some painters.

Code:
void FlickerImage::updateGL()
{
    painter.begin(this);
    painter.setRenderHint(QPainter::Antialiasing);
    painter.drawImage ( QRectF(0,0,800,600), images[image_counter], QRectF(0,0, images[image_counter].width(), images[image_counter].height()));
    painter.end();
}
It works great and I am happy with it on my development machine. Well it does not work on an other machine without qt. I used dependency walker and copied all dll files too it.

The programm started but it did not show the images. After some reading I learned it probably needs the plugins (jpg and opengl). I copied the whole fuccking plugins directory into

E:\flicker_app\plugins
E:\flicker_app\ <- here the imageformats folder etc...
E:\flicker_app\mingw\plugins

And placed the dlls outside and inside the directories. The test machine has an ATI X1250 gpu with the right driver.

No chance. Then I used qt.conf with the path to the plugins to it... no chance. The output was:

Plugins: E:/flicker_app/plugins

Is there a bug or something? The plugins are coming straight from my dev machine (4.73 same as qt creator and the sdk).

Is there a secret path? Or even better, is there a way to know which plugin is missing? For real a simple error message telling where is the problem, trolltech (now I know why you call yourself "troll"tech!).