I too am having this very same problem.
I've followed all the instructions mentioned in this post right to the T and I'm still getting the problem.
- Uninstalled the application,
- Gone to Samsung's site and downloaded the latest version (2.3.0.12035_16),
- Restarted UPNP and Internet Sharing,
- Double checked it is not in USB debug mode,
- Turned off anti-virus and firewall,
- Checked that Kies is allowed through firewall,
- Checked device is being seen by laptop,
Nothing at all works. This isn't the first time that Kies has messed up after an update. Annoying as hell.
How did the OP resolve the problem (other than getting a new phone).