Smoke System Activation

Hi SimmersI am have a little problem...I NOW can't "activate" my smoke system by EITHER the "I" key or from the Drop-Down menu.Don't know what caused it though (must be all the d/loads) :)It happens on all aircrafts. The Drop-Down menu and the "I" key shows and works but like I have to "hold down" the key all the time.If anyone knows hoe to rectify this would appreciate the info.Happy Flying!!