Thank you. I did try eliminating basic causes (updating Turbo Tax, restarting Turbo Tax, deleting the form and putting it in again, etc.). I am using the PC desktop version of TurboTax Home and Business. I did try the suggestion above to put in the actual cost basis, even though it is blank on my form. That does fix the problem, but I just wanted to make sure there isn't an issue with putting something on the form that isn't actually there.
