Have you tried removing the old USGN.dat file from sys folder and replacing with a new one by copying it from CS2D zip file?
Dunno if it will fix your problem but hope it will. Also, would be better if you post your internet connection speed.
@ Tarcisio12354: The quick and dirty solution to fix this would be to play without U.S.G.N. login. So if this is okay for you just remove your login credentials in the options menu.
If that's not an option for you, try clicking the tiny double arrow (>>) in front of your login name in CS2D and wait for a successful re-login. Afterwards try to join a server. If it still doesn't work it might be some weird network/routing problem. Are you behind crazy proxies or thinks like that? Or are you using a public network? That stuff might lead to problems in some cases.