Slyrr here - sorry I haven't been on this forum for a while.
The problem you're having is that I removed the raptorspecies file. For some reason, when you have a custom speices, it WON'T let you join on line games. There are lots of reasons for it, but the bottom line is I had to ditch it. Don't worry that it's not there. The only thing you'll lose is there won't be any 'gibs'.
If you mean the model isn't working at all, there is no reason why that should be. If you put the files into their proper directories, you should be fine - triple check it. I can't count the number of times I swore that I'd put the files in properly only to discover I hadn't. Also check you UT2004 LOG file - if there are any critical errors (like 'couldn't find raptorskins.utx' or something, it'll tell you there.
to download the lastest release, visit:
http://home.comcast.net/~gregfisk/ut2004.htm