Control 24 firmware reset

Anyone know how to reset firmware from 1.08 to previous versions on control 24? I tried the factory reset on the utilities page but still shows firmware as 1.08. is 1.08 the last version? I need to load pervious version of firmware and reload 1.08 as things appear corrupt on my unit. I also tried holding channel select mute and solo while powering like C24 but that did not work. Any ideas?