[Qt-interest] "Black flash" when switching back to Qt app on OSX

[Andrew Stuart]

We have built a Qt app on OSX.

I switch to other apps to do stuff.

If I click on the app to swtch back to it, there seems to be a flash  
of black over the display of the Qt app as it gets painted back into  
the foreground.

If I switch back by clicking on the icon in the dock then there  
appears to be no black flash.

The only additional hint I have is that there appears to be no flash  
over the portion of the screen that is displaying a webkit page.

Does anyone have any idea what this might be about?


Thanks

Andrew