I'm sure it can go both ways, misdiagnosis that is. I had the opposite problem as you, I've had schizoid and schizoaffective diagnoses thrown at me which I believe were really misdiagnoses because my Aspergers(which better explains everything) had not been diagnosed at the time I was given those labels.
When I was diagnosed with Aspergers, I was told by the professional diagnosing me that Autism spectrum disorders rarely exists on their own, and almost always have comorbid mental illnesses in addition to ASD. In my own case, I have BPD, SA, OCD, and Aspergers. The more going on at the same time, sure can make it more difficult to diagnose.