Dependents input screen - months in the US issue

I'm using Home & Business on my desktop.  
I have three children and have the same issue for all three. One of the input screens asks how long the child has lived with me and I answer "for the entire year".  Below that question is a second question, how many months did they live with me in the US? There is a drop down menu allowing the entry of the number of months, inclding zero months. Since I live in Canada, I enter zero but no matter how often I do this the program changes the answer to either 6 months or the entire year. 

Is this a bug or am I doing something wrong?
Thanks.