Your company VPN is likely on a separate network segment than the one you're on when you're in the office.
Can you DNS lookup the IP address for www.juventuz.com on either login place (using traceroute, ping, or whatnot) and see if they differ?
Aha. Vlatko probably nailed it. Sounds like you may have a DNS cache at work that's pointing to old server IPs when Marty probably moved them recently in response to the outages....