tee144.. first that just isn't a nice answer.. Bashing someone for not knowing something is just wrong. and I was always told if your not part of the solution your part of the problem.
Second.. Alex's post was just about worthless as yours.. Because Googling some words and posting other responses.. ah dah don't mean anything especially when its incorrect
Lastly.. all the other posts on solutions for this PROBLEM - are just wrong and plain shots in the dark. because it is NOT a firewall or port blocking problem.. period.
I have perfect internet - no firewall.. Spent time on this issue (as I am working on it for a client) by trying several different internet provides at different locations that I own.. result was always the same
So I went further by checking the traffic with a packet capture.. Apple just is NOT answering back.. the only resolve can come from Apple because my traffic goes out to them and gets no replies..