If you didn’t FTP the files (i.e. corruption in transfer is ruled out), you’ll have to provide more detailed information about your environment. I would first run setup again in upgrade mode to make sure it ran properly.
Nope, nothing.
The MODx log is empty (always is) and the server logs only show some errors relating to spiders:
[Thu Dec 09 15:08:18 2010] [error] [client 64.124.140.232] request failed: error reading the headers