I had a heck of a time trying to get Kies or even my USB connection to work. I only needed Kies so that I could update the Firmware to 2.3.5.
What I found though is a menu option that hopefully should work for you.
Go to the Setting Application. Look under Wireless and network -> USB Settings and you should see 3 options there - Samsung Kies, Media Player, Mass Storage. I set mine to Mass Storage and whenever I connect to a USB cable, it prompts me that it is USB Connected and allows me to select to "Connect storage to PC". Press that and after a few seconds, you should be able to see both the SD Card (internal memory) and the External SD Card (your physical card if you have one).
Hope that helps...