GetChar problem

I'm new to psychtoolbox so I apologize if this is a stupid question.

When trying to use GetChar or CharAvail I get the following error:

INTERNAL PSYCHTOOLBOX ERROR
error: PsychError_internal
general description: Unspecified error, probably a Psychtoolbox bug
specific description: Failed to load the cocoa bundle.
module name: CocoaEventBridge
subfunction call: CharAvail
file name:
/Users/ingling/Desktop/1.0.6/PsychSourceGL/Source/Common/GetChar/COCOAEVENTBRIDGECharAvail.c
function name: COCOAEVENTBRIDGECharAvail
line number: 51

Does anyone know why or how to fix it?

I'm using an 20-inch iMac G5

otherwise should I use KbCheck?
Thanks,
Michael Nguyen