Policy is often not to reply to unsuccessful applicants, which might explain why you haven't had any answers. Personally I think this policy is (a) rude and (b) unhelpful as it doesn't let you find out why an application has been unsuccessful. Having said that, you could try calling some of the schools you have applied to and asking why they didn't select you for interview - it's perfectly reasonable to ask for feedback. The other thing might be to ask a few people to review your applications and solicit constructive criticism. I've found other probationers to be the most help in this: my established colleagues all too often read an application, say "That's great, I'd give you an interview" and move on whereas a fellow probationer will be looking at it with a much more focussed eye.
But it's a tight job market out there, there's a lot of competition. I suspect even a great applicatino and stonking reference will not be enough to guarantee an interview in many cases.
Hope this helps.