No.
Try connecting to a VAC server in HL2DM or DoDS. Alternatively you can try TF2 or L4D although they are a different engine and the problem may not be affecting them.
If you have the problem in the other games listed above:
1. Turn off ALL firewalls
2. Set router to DMZ your port/IP/MAC
3. Disable all proxies
4. Do a complete uninstall of Steam and manually delete all remaining files (save your configs)
5. Reinstall CSS ONLY and try to connect to a VAC server