samsung galaxy s - Odin not allowing firmware to be flashed

I'm following the instructions here to try and upgrade the firmware to I9000XWJS8: http://forum.xda-developers.com/showthread.php?t=846913

As soon as I hit start it does nothing, as you can see in the message window it says it's failed. It does this with JS8 or with the Gingerbread download, in Odin 1.7 and 1.3.

What's going wrong? Also, should the phone be in USB debugging mode or regular? I've tried both to no effect.

Answer

The phone should be in Download mode:

1. Take out the battery


2. Plug into USB (apparently skip this if you have an i9000 -- see comments)


3. While holding both volume buttons (Note, you may need to hold Home+VolDown instead)
   
   
   
   1. Insert the battery
   
   
   2. Click the power button
   
   
   
   


4. Phone should go into Download mode after a few seconds:

You may need to disconnect from and reconnect it to the computer after this for Odin to see it.