Line 5a being more that the amount from box 1 of the Form 1099-R implies that you have entered more Forms 1099-R than just the one you have mentioned here. If you are married filing jointly and your spouse received a Form 1099-R, make sure that you've marked that Form 1099-R as belonging to your spouse. If you also have an IRA distribution, make sure that it appears in the IRA section a not in the Pension and Annuities section. (A distribution from a traditional IRA must have the IRA/SEP/SIMPLE box marked on TurboTax's 1099-R form in agreement with the marking of this box on the Form 1099-R form the payer.)
Since you are apparently using the CD/download version, in forms mode you can right click on the amount on line 22 of the Form 1099-R Summary and click Data Source to see the Forms 1099-R that make up the total.
