My GMAT score dropped 30 points after two years?

Hello,

I took the GMAT in Aug. and Dec. of 2007 as I was graduating college. I am almost 99% certain that my scores were 670 and 690 respectively. I applied to a few schools for the heck of it and actually got a phone interview with Carnegie Mellon Tepper, but alas, was rejected and was told to get a few years work experience. Well, it's been a few years and I've accomplished a few great things in my career (IMO) that will really help me get in to business schools. So I called GMAT and asked that they resend me copies of my GMAT scores, and to my surprise my scores were 640 and 660! This is 30 points lower than I remember!

Is it possible for the GMAT to lower your score after two years? I read the fine print and it says that the scores represent my position among the average test takers from the last three years, so is it possible that people are getting better at the GMAT and my scores got lowered? I'm really pissed, because a 690 is a fairly decent score for some T15 programs, but a 660 is pushing it.

Help?!?! I'm going to call some of the schools that I applied to and see if I can retrieve my old application. Maybe I can prove that my scores are higher than GMAT is currently reporting?

Thanks.
-Adam