Humm--not sure...I do not know much about the undergrad/med combined degrees. I know that it says in the AF contract that permission will not usually be granted for any combined degrees, and that your DO/MD program has to be a program that you plan finish in 4 years. Also, the scholarship has a maximum length of 4 years.
My best suggestion would be to contact a recruiter and ask any questions that you have to him/her (just remember that there will be a positive spin on anything that he/she says).