I have had the phone talking to the PC and Kies in the past on the stock software and on various other builds. I have since upgraded to I900XXJPM (Froyo) and the phone does not even connect to the PC.
I installed the most recent version of Kies and it still does not connect. I manually installed the Win 7 64 bit driver and this is where things start to go wrong. The software appears to install fine and then starts loading the driver for my device. The phone is not connected at this point and the driver comes up with an error saying something about a

 

I removed Kies and deleted all references to Kies in the Reg as per the following:
http://androidforums.com/samsung-galaxy-s/160983-cannot-install-galaxy-s-driver.html
I installed the win 7 64 driver and the phone is now accessible via windows and Odin. Job well done Darkone69. Not so sue I want to load Kies again...