I didn't try upgrading my version because my friend managed to make it work, anyway, I can make the button show, but it is not responding to any of the mouse over/click...

PANEL* panel2 = pan_create("button_toggle(0, 0, red.bmp, green.bmp, blue.bmp, white.bmp, clickMe, leaveMe, overMe);", _VAR(999));

And the image of the button is always in green.bmp, which is the off state. The clickMe, leaveMe, overMe are just simple functions to do a cout message.

Do you see any mistake in that line?