After downloading and installing the latest Webkit Nightly Build (WebKit-SVN-r32008.dmg), no website can be reached from behind the NBC Universal Proxy, including the Webkit websites. Regular Safari 3.1.1 will load pages.
Do previous nightly builds work?
(In reply to comment #1) > Do previous nightly builds work? Builds r31981 and earlier work. Builds r32008 and r32012 have "Failed to open page"
Latest WebKit r32778 works through Corporate Proxy now.