Kies won't connect to Galaxy S2 It just displays Connecting... forever when I plug in the phone (through USB), and nothing else happens. What should I do?

I just installed Kies, v2.3.0.12035_16
I had the same problem. I fixed it by reinstalling the latest version of Kies and deactivating USB-Debugging BEFORE I connected my phone (Samsung Galaxy XCover) the first time.