Did you enter any qualified dividends and/or capital gains on your tax return. If so, your taxable income on Line 15 of the Form 1040 might have the taxes calculated using the Qualified Dividends and Capital Gains Worksheet instead of the tax tables on Line 16.
Do you have any Self-Employment Income? If so, the net SE income is taxed separately using Schedule SE for Self-Employment Taxes on Line 23 of the Form 1040.
