debt ratio calculation

With the recent changes to the credit markets how do lenders count rental income in debt to income ratio?
More specifically, I am interested in learning the average requirements that conventional and FHA lenders use in making debt to income ratio calculations with regard to rental income. Is there a minimum number of months that I have to prove that I have been receiving this income? If so does anyone know how many months that is?
By the way, I have included my rental income on my Schedule E, but the property was under rehab for 8 months of the year, I didn’t get tenants until the last quarter. So, my Schedule E, won’t reflect the true nature of my current situation.
Any help would be greatly appreciated. Thank you!
2 years


