This happened to me as well. I unplugged the phone, quit out of kies, then started kies up again. It updated again then I plugged the phone back in and it worked. Hope this helps.I'm having a lot of trouble getting my phone to connect to my pc via Kies.
I have tried reinstalling drivers, changing USB connection options on my phone, updating to the latest Kies version. Nothing I do can get the software to recognize my phone in Kies mode. I can connect the phone as a mass storage device to transfer files, but this doesn't give me any options to update to 2.2
Anybody else have issues?