Every time VAX checks for an update (easy to trigger by changing the checkVersionDate reg key and restarting), it thinks there is one. I have to use a proxy to access the internet so it's possible the false positive is caused by that. If it takes IE's settings it ought to work.
Looks like a simple ShellExecute call with a little info (current version = 1557, button = yes). The landing page obviously says "no updates available".
Setting up Windows to block the internet is not going to be easy. I'm in a situation where a program not using the proxy can't even access DNS. I suggest the return values from whatever web code you're using ought to be be checked more carefully.