I had the same problem. It turns out I had marked that I had been reimbursed by my insurance company more than the value of my items. This was causing TurboTax to see an error when reviewing the form, but for some reason it marked box 4 as incorrect and not the form values.
You'll need to go back to the income and deductions page to edit the values of your items. Make sure that the insurance reimbursement is less than or equal to the fair market value of the items.
