This is 2009 and you must have full documentation and credit that meets the guidelines.
I suggest that your finance report his income and you work on cleaning up your credit and then re-approach purchasing a home in 2010.
Some lenders impose credit score restrictions on borrowers, therefore you must meet their minimum credit score (i.e. 640) in order to qualify for a home loan. On average, most lenders require a 625 credit score.
As for the amount of income you need to purchase, that depends on how much house you're trying to buy. Here I suggest you contact a lender and ask them to review your profile (i.e. IRS reported income, monthly liabilities, assets, etc.) so they review your credentials. Also, they can evaluate your credit. Among other corrections, outstanding judgements must be satisfied before you can make a home purchase.
Due to the record number of foreclosures in the marketplace, lenders are more conservative. Credit score alone will not qualify a borrower.
Hope this helps. Email me if you have additional questions.
Let me know if I can help you any further