Have you updated your video card drivers?
Agree with Curt. Your graphics driver is damaged. Update/ reinstall.
yes i do
and the new at drivers are worse for cs6
What OS and video card?
i noticed a mask brush big size lag with areo off
without shutting down photoshop , i turn on areo via visual style , the brush become no more laggy
windows 7 32bit
but the brush big size become laggy with areo off
to uninstall the ati drivers should i use Driver Cleaner.NET ?
i installed via device manager , because i had some issue to uninstall and re-install