I am unable to get all of iTunes to load

Hello,

I just purchased an iPhone 3G. I have downloaded the latest version of iTunes and everything works except the Moble Me part that allows me to synk my phone. I have had my computer into the Apple Store and they couldn't figure out why it would not work. I took it to a computer tech and he said there is not reason it should't all load. We toke down the firewalls and it still would not load the iPhone part. Sooooo do you have any sugestions. I hate to buy a new computer just to get iTunes to synk. Everything else works just fine. I have a windows XP.