if ur iphone operates similar to older generation ipods....u will need a powered hub for the nit to recognize your iphone via usb
if u r using bt i would start the pairing with the iphone ie let put the nit in discoverable mode and let the iphone discover it(my memory tells me that is the way i have had the most success pairing phones with my n810 in the past)

ot> how is the 3g compared to 2.2.1?

see if this helps you
http://lifehacker.com/5175640/intern...g-on-iphone-30