Per Wikipedia, when this game came out, people were under the belief that ALL the games would play online. Apparently, this isn't so. You can read the article at http://en.wikipedia.org/wiki/CNCTFD
Now, apparently, there is an unofficial patch out there that will give you online play, but it's not very reliable. The link to it is listed in the wikipedia article I posted.
Ensure you have applied all patches to the game and see if the unofficial v1.03 patch helps. I'm assuming that's what you were talking about.