Flickering display on Mac OS X Intel.

Hello,

I've used Amaya for years on Mac OS X PPC 10.4 then I switched on Mac OS X Intel 10.6.
Often the display is flickering while typing or moving with arrows of page keys.
When I clic in menu bar the display becomes correct for a while.
See below attached screenshots.
It seems like some issue in text buffering... My guess.

How to get rid of that?

Thanks, Pascal.
http://blady.pagesperso-orange.fr