Although it is rare, one school to which I applied had trouble downloading my application materials and, essentially, was unaware that I had submitted my application (this despite the ERAS site listing all of the dates that sections of the application were downloaded from my box). This is a computer glitch on the school's part, and was only picked up because I was doing an away rotation at that institution. I was told all of these errors had been rectified, but you never know. I contacted most of my remaining schools and everything was kosher.
I would agree with the earlier post re: contacting schools this week if you have not heard anything. If you have 240+, above average grades, applied to safety schools, and have a completed application, I would say it's a little surprising if you don't have an offer yet.