Am I responsible for my new husband's tax debt?

My husband and I married in 3/2009. At that time, unbeknownst to me, he didnt file taxes for two years. So when he finally filed 4/2009, he found out he owed a lot of money including penalties. We do not own any houses and we dont have any children but I do expect a good return (I have already calculated this). He didn't make much money last year either ($19k compared to my $31k). I want to receive my full return and not be liable for his tax debts. Should I file married-seperate (MS) or married-joint (MJ)? Can I utilize the "injured spouse" exemption when I file either way (MS or MJ)? How should I file each year until he pays off his tax debt (he isnt currently in a payment agreement)?