Problems after installing ios4! black screen and error 1602

Yesterday I updated the firmware to 4.0 on my iphone 3g.

After the update I unplugged the usb and used my phone, it seemed a bit sluggish but I thought nothing of this. I put the phone to sleep but the phone would not wake! The only way to make it wake is to reset the device by pressing the sleep/wake + home buttons for ten seconds.

I thought that restoring the device may solve these issues but I cannot do this as I keep getting “error 1602”.

I have uninstalled and reinstalled itunes an the twice, created a new account on my mac, tried it on two different windows machines and used different usb cables – every time I get an “error 1602”.

I have also tried resetting my phone in settings > general > reset > reset all settings. This has not helped.

Any help solving this without going to a mac store would be greatly appreciated!!