As discussed extensively by posters in other forums, the iPhone 3G headphone problem is a HEATING problem. Period. I myself have installed a new headphone jack assembly and a new docking port, to no avail. I've tested the heating issue numerous times to verify that it's the problem, and confirmed it's quite reproducible. Unfortunately what this means for all us 3G users out there is that there's no 'easy' fix for this issue... unless someone comes up with a better logic board cooling method, for example. Liquid sodium, anyone?