Sure, but when you use a high-level language for low-level functionality you're always going to be vulnerable to changes in how the OS interacts with the run-ti

Sure, but when you use a high-level language for low-level functionality you're always going to be vulnerable to changes in how the OS interacts with the run-time library of the language. I'm amazed that Psychtoolbox's use of Matlab has worked for this long, but, like Flash's obsolescence, maybe it's time to use a different language. In any case the problem is not OSX but the implementation choices made by Mathworks in Matlab for OSX.