I had many ear infections growing up...even in highschool/college, I remember crying from the horrible pain...My son also had numerous ear infections...
My take on autism/ear infections, etc? Although autism is primarily genetics, I do believe those same genes cause many people with autism to have deficient immune systems. With the deficient immune systems, many people seem to truly be allergic to cassein/milk, etc...however, they are hardly diagnosed with this, especially if it's just a sensitivity...and this allergy, although it might be mild, does cause mucus and fluid in your ears...thus leading to ear infections...