Events issues with QGraphicsView on MacOS X at high frame rates

I´m a stellarium.org developer and I´m experiencing some performance issues with QGraphicsView.on MacOS platforms. We have not observed such a problem on Linux (Ubuntu 8.10)

I've been using qt 4.7 Tech Preview for some weeks on MacOS 10.5.8. I compiled the sources with default options so Qt now uses Cocoa instead of Carbon.

We use QGraphicsView with a QGLWidget viewport and the option NoViewportUpdate. We manage the updates by ourselves since we have an adaptive frame rate system (battery saving optimization)

The painting of the scene seems to be ok but apparently there are problems with events treatment at high frame rates (Events are ignored? ) I think I´ve been able to reproduce the problem in one of the Qt examples (elasticnodes) At low frame rates (<250) both the painting and the events treatment work fine but when increasing the number of frames the gui becomes less and less responsive to the events (>250)

Please find attached the modified code of the example. I've just changed 4 lines in the constructor of Graphwidget. You can try to run the example with different frame rate values to see how the responsiveness decreases.

Thanks in advance,

Diego.