Not uncommon at all. I'm in a slightly different boat as I'm graduating med school late and doing an accelerated MPH this year while I apply to residencies. I'll be receiving both degrees in May 2012 (hopefully).
They accepted my MCAT scores (2005) even though I also submitted GRE scores that were way old (1995) from when I was in college. I took GRE then b/c I applied and went to grad school for a masters long before med school.
There are several schools that have accelerated MPH programs (since the traditional MPH is at least 2 years) that you can do in a year or less: Hopkins (11 mo), Harvard (9.5 mo), Columbia (~10 mo), I think also Berkeley, UNC, Duke...I think if you search, someone asked about 1 year MPHs and that question was answered before. Sometimes, the requirements are less or waived as transfer credits if you have a medical degree or took relevant grad level courses before that did not count toward a degree.