PX41CX: Strange disply change

[rawi]

Hi,

I tried my new PX41CX and it worked really well and I like it.
But one strange thing occured with the display: I used a program with 8 MHz speed on battery and it ran quite well (execution time 6.25 minutes). Then I ran the same program with the same parameters with 32 MHz speed and power supply attached for testing purposes. The program ran through with the same results. But during the run the flying bird fell apart in a lower and upper part and the disply switched to light characters on dark background. How can I switch back to dark characters on light background?

Thank you!