iphone 3G wont appear in itunes or desktop

HI there folks, I recently upgraded the OS X from 10.4.11 to 10.5.8, before the upgrade the iphone would automatically sync up with the itunes and do what it does best. However now nothing happens, iphoto will load up and show the pics on my phone, but itunes wont detect the phone even if i shut it down and reopen it with the phone plugged in. I also restarted the computer and phone and still nothing, Im running itunes 9.0.2 and Im sure it was the same version when I upgraded to leopard I believe.
imac intel core duo Mac OS X (10.5.8)