I'd agree with the above post. I don't go to a medical school considered anywhere near the top 25 and I've gotten interviews at nearly everywhere I applied to including Boston, UCSF, Hopkins. My fellow classmates have interviewed at great places too.
However, that being said one of my former classmates (an MD/PhD no less) had applied to a top surgery program and didn't get an interview at first. He later called and was offered an interview upon reconsideration of his application, and discovered later somehow that his app had not been considered at first due to his no-name medical school. Happily, he interviewed great and matched there and our school matched another student there the following year.
That one freak story however aside, I would agree that grades, letters, board scores and research are far more important than name of medical school.