windows thinks you have a network connection but its not one that connects to the internet.
Can you try the following. Look at what connections you have and disable them and only leave the one you need enabled. If you say "but I only have 1" then we need to find out why its allways connected. Can you post what it is and what it does.
[Edit] had a play and i've added a check now for internet. It looks for www.microsoft.com and if finds it assumes there is a network otherwise fails network check.