If you entered your securities transactions by entering your T5008 slips in TurboTax, you shouldn't enter them again. It is possible that you might have selected something in the Capital Gains Profile page. If so, just go back to the Capital Gains Profile page and unselect the "Sold stocks, bonds, real estate, other capital property, or sold qualified small business corporation shares and/or qualified farm property and you have a capital gain or loss to report" check box. It is for people who have sold securities but don't have a T5008, or for people who are reporting capital gains not reported on a slip.