Strange Behavior When Removing Address Lines

I'm writing a client side script that runs on a Suitelet page and I've encountered some strange behavior.  My code removes Address lines based on the users request (it's an address management Suitelet).  The code loads the customer record and uses the record.removeLineItem() function.  The code loops over the users selections removing from highest line num to lowest (so the indexes don't change).

Here's an abbreviated version of the code:

deleteArr.sort(sortArr);        for(var d=0;d<deleteArr.length;d++)    {     customer.removeLineItem('addressbook',deleteArr[d]);    }

The sort function:

function sortArr(num1, num2)  {   return (num1 > num2) ? -1 : (num1 == num2 ? 0 : 1);   }