I don't think I've come across that one yet, so I don't know what it is doing.
But have you verified there is no indication of an employer retirement plan? Double check any W-2s, and double check the employer retirement worksheet if the client is self employed.
Yes, that was the first thing I checked. But regardless of whether the retirement plan box is checked (and there is no other Sch. C business) ProSeries is computing and addback on the MN return based on AGI. The correct treatment should be there is only an addback if taxpayer or spouse are covered by a retirement plan! Please correct this error!