loving 5 year old in own world

have a very loving 5 year old boy. He has always been a bit behind, and seems to catch up eventually for the most part. We had him screened for Autism, and they said he had a few of the symptoms but not enough for them to say it was autism. We thought maybe he is immature for his age, so we kept him in preschool one more year. He is going to start kindergarten late august, and here i am worried again. He just seems different. He is always humming ( though its only when he is happy or eating).  He seems like he is in his own world. He does have a few friends that he plays with, but sometimes he does or says inappropriate things, and it seems like he doesnt know any better.  He is always interupting conversations, and repeats things alot.  I am not sure where to go from here. I worry that he needs to be protected, he is very sensitve, and his communication skills arent that great. I know what he is trying to say, but other people would not.  There are days where i think he will be fine, then something happens where he loses it and throws a huge tantrum because his socks are the wrong way or his balloon popped and he cant handle it.  I dont know if this is normal, add (my husband has it) or does he have a learning disability?

[Sally44]

I've responded to you rpost in the Child Behaviour forum.  I am a parent of an 8 year old boy on the autistic spectrum.  I know so well those sock and sound incidents.  What is your son like with having his hair/nails cut, clothes tags?  Does he over react to light touch or a slight scratch, and yet appear not to feel pain at another time?  What is his response to sound like the vaccum cleaner, sudden unpredictable noise?  Does he sometimes not respond to his name or cover his ears?  Does he repeat things people say or things from TV or films?