It doesn't seem to be IOS, more or less the provider
I bought an AT&T Iphone 4 earlier this year, and in the past few weeks my business bought us Verizon Iphones in place of our former Blackberry's from Verizon. On my AT&T Iphone, I can connect perfectly to my macbook, and all my other computers and devices. On Verizon however, it cannot connect to anything but other cellphones or bluetooths, and it wont accept data transfer from any of my cellphones other than the old Verizon Blackberrys we had. I'd also like to point out that we had a similar problem with our blackberrys too! Since I organize the bills, I would of noted something like restricted bluetooth on it... but Nope, its not on their. I think it might be Verizon themselves restricting "free data transfer"... I'm not conclusive on this, but I will indeed try with an upcoming phone purchase from them.