This question has been out there a while, but to make it simple for anyone else looking at this type of situation, let me clear things up!
Most (no one can ever say always or never) lenders will require your rental income to be seasoned at least one year. They will want to see the rental income on a tax return as proof that is your true intention for the property.
We have been helping people rent their current homes to a tenant and they are renting a home for themselves to move into, then a year later they are able to purchase a new home. It's a few extra steps but you need to understand that the lenders out there have been burned by to many people out there renting out their homes and then just one or the other go into foreclosure when things get tough.
So, the answer is you need to season your rental for one year!