Android : ListView IndexOutOfBoundsException

i"m getting crash reports on IndexOutOfBoundsException inside my adapter , it was never happen on my device so i don't know the scenario .

on my getView it crash (itemlist.get(position)):

public View getView(int position, View convertView, ViewGroup parent) {
    View v = convertView;

Object i = itemlist.get(position);

and of course i override getcount , as i mention it was never happen to me but i get reports that is happen to usersaa sometimes

public int getCount() {
    return itemlist.size();
}

any ideas how could it be ? and how to prevent it ?