Thankfully you will still qualify for the tax credit even if your father co-signing for you does not. A scenario quite similar to this is on the IRS website:

S2. Taxpayer A is a single first-time home buyer. Taxpayer B (parent) cosigns for A and does not qualify. Both names are on the mortgage. Can Taxpayer A claim the credit and, if so, how much?

A. Yes. Taxpayer B is not a first-time homebuyer and cannot claim any portion of the credit, but A may claim the entire credit ($7,500 for purchase in 2008; $8,000 for purchase in 2009), if the home was purchased as Taxpayer A's primary residence.

http://www.irs.gov/newsroom/article/0,,id=206294,00.html

Best of luck on your home search Michael. If you aren't already working with a Realtor, feel free to contact me with any more questions directly.

Rider Rodriguez
rider@parkerandklein.com