If you are using Network Connect on Ubutnu 9.10 (or any other system with avahi-daemon), if your company's internal networks contain a .local domain, you will have to disable avahi, otherwise, while nslookup will return the correct address for internalhost.mycompany.local ping, ssh, firefox will all use the mDNS to query your local network and fail.
Hopefully this will save someone some wasted time.