Hello,
The issue might be related to the encoding of the file or to some additional text that is being added by your text editor. I personally recommend NotePad++ for such things and as FTP client Total Commander or FileZilla. Try to FTP using the FTP client and see the code inside the wp-config uploaded on the server.
Regarding the network I suggest you check this link :
http://codex.wordpress.org/Create_A_NetworkIf nothing above works you should email support for additional help on troubleshooting this

- Marian