I am not familiar with the Optic 6 however are you talking about starting up in Idle up (stunt mode on some radios) or normal mode? Most radios inhibit the stunt mode, at least untill you have started up in normal mode then you switch to stunt mode.
Usually you start off in normal and at about 3/4 stick you switch into stunt or idle up mode.
I hate to ask this but are you a experienced heli flier?