Double Buffering?

We are having a subtle problem with the screen updating of a ptWidget (I
guess, since I did not write the software). The problem is that it does not
clear the widget when writing to it.

Rigth now we are writing some data on it. When writing new data, the old
data is not erased and the new data will be just overlayed. Also, the actual
bacxkground, i.e. the desktop, is also kept and not erased.

The identical software works OK with older versions of QNX than 6.2.
It seems to fail on the professional edition, QNX6.2.2.

I wonder if there are some new switches for clearing, updating or swapping
buffers, somewhere, that has changed in the new QNX? Or if some graphics
libraries has changed?

We have confirmed that it is not the graphical card (by running the software
on an older QNX, but on the same machine)

Any help appreciated :slight_smile: