That's a really nice shot - how did you get the saturation on the sunset -did you use exposure compensation?
I've just bought a D200 (I was in Malaysia and couldn't resist the opportunity) and am using the 18-70mm with it. The only focusing difficulties I've encountered so far have been carbon unit (ie user) error - choosing the wrong focus zone via the viewfinder. I was originally concerned about my choice of lensbecause I'd have liked to get the unavailable 18-200. But so far, I'm happy enough - if you've a flickr account, you can see the EXIF data...
http://www.flickr.com/photos/totally...7594106594124/
http://www.flickr.com/photos/totally...7594106594124/