No bother; appreciate your willingness to help. Actually I found the problem, and it's not a TurboTax bug at all! TurboTax is actually right (too complicated to explain here). It would help, however, if TurboTax had a "trace" facility with which you can give it a form/schedule and line number, and it would tell you which inputs were used, and how, to calculate it, like you could in a spreadsheet. Even a one-step backtrace would be immensely useful (and could probably save them a lot of customer support costs)!
