My 1040 shows the box checked as well, and I'm not even married.
With how many people seem to be having this issue, I really don't think it's something we did, but a software problem. If you go through the process there isn't a single question that asks anything about a spouse being claimed. I filed as single. It only asks me if I personally can be claimed as a dependent. If there's never even a question about it, then it wasn't me that screwed up.
Very upset at TurboTax over this. And I can't even ask them about it unless I pay $30 and upgrade to a paid version.
