i am still not able to figure out why my software instruments will not play with my musical typing option. they seem to show up when i select them, but when i get to typing, there is only a plunk sound. could it be the keyboard? it's an older mac/keyboard, a G4 CPU but it has enough memory and i have uninstalled everything but garagegband and firefox so there is space to do what i need to do. or is my mac just nuts?