That was my thought. Asperger's doesn't seem to be a disease that would really tax the system the way that HIV or TB would (which is really all they cared about for the 457 visa, and we front-loaded our medicals for the PR application).

If they kept out everyone who had a minor mental or physical disability, they would be shooting themselves in the foot. I would think that if people who are diabetic are able to come in, Asperger's should be almost a non-issue.

I would keep asking, like Dolly says. You could also contact the DIAC themselves and see what they say. They may not be able to give you an absolute "yes" or "no" because a lot of it will depend on circumstances, but unless they can say "no, we don't allow people with Asperger's to immigrate permanently here" then hope is alive!