"pointer being freed was not allocated" on ESC

I’ve just started a project with Xcode 4.6 and OF 0073.
If I click on “play” button the application start and everything is OK.
If I click on “stop” button the applicaiton quit and everything is OK.

But… if I press the key ESC on the keyboard… this is what i get:

testDebug(599,0xac00ba28) malloc: *** error for object 0xbffff7c8: pointer being freed was not allocated
*** set a breakpoint in malloc_error_break to debug

on this line of testApp.h:

class testApp : public ofSimpleApp{  

what’s that?