Run Qt Widget program on VPS with Xorg running over VNC

I want to start simple Qt program on my remote VPS. So I installed Xorg, BlackBox and x11vnc. It works good and I can connect to the server with VNC client. I see grey screen and if I run xterm & in BASH shell (I connected over SSH to the server) I see xterm window in VNC screen. I've downloaded and installed Qt package with visual installer without problem. Also I've compiled test Qt program. Up to this point everything is fine. But when I run the test program I get lots of warnings :

QWidget::paintEngine: Should no longer be called
QPainter::begin: Paint device returned engine == 0, type: 1
QWidget::paintEngine: Should no longer be called
QPainter::begin: Paint device returned engine == 0, type: 1
QPainter::save: Painter not active
....
over 100 lines here

Xorg server is running, I started it with startx &. Also, as I see, X server implicitly started BlackBox. So what I have to do more to start Qt program?