Connecting via VPN to a customer site has always caused problems with me trying to access the local network. My computer would try and use my VPN credentials to access the network, and naturally fail. A co-worker showed me the “cmdkey /delete /ras” command that would clear out those credentials so browsing the local network would work.
So I, running Vista, fired up a command prompt with administrator privileges because I figured the cmdkey command required them. After running the command, I tried browsing the network and failed. Running cmdkey /list showed no credentials but my exchange credentials. I started a command prompt with regular privileges and ran the cmdkey /list. Sure enough, there were my dial-up credentials. Running the cmdkey /delete /ras cleared them out and everything worked.