Anyone tried to use the NumberOfElements property to limit the number of elements used from an array in a ComboBox?

I tried to use the first 8 elements of a 12 elements, two dimension array for a ComboBox by putting a '8' in the NumberOfElements property.

But when I ran the form, I always get the whole array in the drop down list of the array instead of the first 4 rows (2 elements per row.)

So is this a bug or am I missing something?