Call the IRS and ask. If you don't like the answer call back you may get one you like.
Record the time, date, and agent badge (it is my understanding that all calls are recorded, so proof that they told you what to do).
I found lots of information on the IRS site, including legal separation info. Search irs.gov for divorce and/or legal separation.
[This message edited by Take2 at 8:40 AM, February 13th (Thursday)]