A few years ago I spent hours debugging and getting gray hair until I found out that a 1 (one) was in fact a little L. Never name a variable l !hehe actually the worst bugs have exactly ONE character... Like "," instead of ";". These are things one looks for for days
i, j, k, l, m as loop variables.. you know the game 
Miscounting by 1 is actually the unbeaten No 1.
