Depending what what the final AGI will be once you have completed the return in it's entirety, it's perfectly possible for the tax rates to be the same for your specific scenario. So you really can't make a final determination until the return is completed and ready to file.
Remember, the program can only work with the numbers "at this specific point in time". As you enter other numbers for income, expenses, deductions, exclusions, etc, things will change. I guarantee it.
