Just a quick reply:
1) You're right, that looks like a mistake.
2) It's unlikely TT made a calculation mistake, so what's more likely is that something is entered incorrectly, so go over everything and figure it out. That's a big enough discrepancy you don't want to ignore it.
And in a situation like this, I think it will be difficult to give someone in a forum enough information to figure out where things have gone awry. If you can't figure it out, you might want to get someone, either in person or online, to look over your return, either a trusted friend or a professional.
I would begin by going back to the 1099s you input and make sure everything is properly input, but you seem to have already done that. Still, like you say, something seems awry!
