windows xp wont recognise iphone 3G

iphone is not detected in windows the camera wizard wont pop up when i try to sync or backup the phone freezes the i have to hard restart the phone. apple store has replaced phone twice i wiped the hard drive and reinstalled windows still have the same problem all this since the 3.1 update and apple support no help the support tech wont even email me back anymore i exspect this from microsoft not apple they need to hurry and fix this problem others are having other problems battery dropped call etc it would be nice if they just rollback the driver i did every step tech support has and still no resolution. heeeeeeeeelp
dell optiplex g270 Windows XP Pro none