I tried just changing the amount to $600 as we are filing jointly, but that did not seem to work either.
When will Turbo Tax get this fixed? We are encouraged to file early by Turbo Tax, but then there are these issues and no way to report them directly or get any satisfaction or notification that they have been fixed. Since this also affects your overall AGI, this is a serious issue and will also impact state taxes in many if not most states.
