One thing I would say is that not having your 2009 tax return will be a potential impediment to ANY lender you will be working with. If you need to go to a different lender make sure you explain to them that you don’t have a copy of your return.
One thing you should be able to get from the IRS is a letter stating they did cash the check that you sent in. This is slightly better then nothing but you will need the return and you will have to submit it to the IRS anyways so you may as well do that immediately.