If you use -webkit-perspective and -webkit-transform-style: preserve-3d; the two-finger scrolling on elements with overflow:auto; stops working. An live exmple can be found here http://www.martinjansson.se/iphone/icook all the code is visible trough 'view page source'.
Please file bugs in Safari on iPhone at http://bugreporter.apple.com. For reference, I filed this internally as <rdar://problem/6471886>.