I have a 10.6.8 server that has no trouble functioning poperly. It is out library server located at library.mchs.net.
BUT we cannot access the interent at all from the machine, or even ping another device on the interent.
The server address is public and on the DMZ, and the IP has been added to the exclusion lists on both SonicWall and Cymphonix Composer, so it appears to be a setting on the server itsef.
I seem to recall that there is a "routes" file somewhere the determines settings that might override the network settings on the server proper... this happened to me years ago but cannot remeber the path... if that's even it.
If I set up a test machine with the same IP settings it gets on the interent just fine.