Found this on a Mills Reel Pack

[oldslotman]

Put a Lemon over the cherry and leave the plug in. you most likely have the wrong reel strips on the reels.

[oldslotman]

There are two different reel strips for the first reel. One has a lemon in place of a cherry or vice versa. if you remove the first plug it will most likely pay out correct. There may have been a different reel strip on the first reel at one time that had the lemon in that position and plug was put there for that reason.