I had the same issue. Spybot Search and Destroy on my PC adds address to the c:\windows\System32\etc\HOSTS file. It seems that Cisco VPN does not look at the bottom of this big list, must only look down a finite amount of lines. I moved my Cisco VPN addresses to the top of the HOSTS file with all the other stuff after, and it works. You will need to use administrator writes to update the file and change it from read only to save.