I think that it is essential to change your personal statement, especially if you are applying to the same schools as you did the previous year.
My first year applying, my PS was crap. I composed it while I was filling out my AMCAS, and looking back on it now, it's embarassing. I think it made a big difference in my rejections. This past application cycle, I think my PS was much better, but since my MCAT scores weren't improved it didn't really matter about my PS. When I reapply for the entering class of 2007, I'm changing my entire PS, I'm already working on it now.
You can work being a reapplicant into your essay. Use it to show your determination and resolve. Explain what a year's worth of rejections has taught you about yourself and about the world. Be humble, but be dedicated to your ultimate goal. They should be able to tell that you will do almost anything to become a doctor, and that even if you have to apply for the next five or six years, you will not stop until you have achieved admission.
At some schools, being a reapplicant is different than being a first-time applicant. I know at one of my state schools, ECU, half of their entering class is usually made up of reapplicants. many schools evaluate reapplicants differently than first-timers.
And just so you know, I'm working with Phil_Anthropist to get this year's personal statement reading/critiquing thread started in Pre-Allo. I read/edited at least 100 essays last year, some of them went through several drafts. I also helped out with some secondaries. Feel free to PM me or email me (gotta add an email to my profile) and I'll try to help out in any way I can. I have a B.A. in English, and I've spent several years working as a writer for a newspaper, and I've been working as an editor of scientific research papers for about a year. I'll be glad to help out in any way I can.
don't give up, EMT! It will happen, it's just a question of when.