Is it possible to add 3rd, 4th etc. integer variables to the example exampleInt​GAMULTIOBJ​.zip?

The file exampleIntGAMULTIOBJ.zip was given as a response to the question Is it possible to solve a mixed-integer multi-objective optimization problem using Global Optimization Toolbox 3.2.4 (R2013b)? asked by the Matlab Support Team on 25 Oct 2013. I really hope you can help out with adding integer variables.

I tried to add a variable, then constrain this variable to be integer just like the first two variables, by addding IntCon = [1, 2, 3] to each of the custom functions (which are int_crossoverarithmetic.m, int_mutation.m, and int_pop.m). And I added the third bound to be: lb = [-20, 20, 20] and ub = [20, 20, 20]. For testing, I added the 3rd variable to both objective functions just by stating + x(3) Yet when I run it, the third x variable is not integer. What am I missing?