I just ran into an odd issue. I started loading
http://www.slashdot,org, then when it had partially rendered I hit Back. I then hit Forward. OmniWeb was now showing the same partial rendering of Slashdot, with no loading status or network activity, as if that was the entire page. Reloading fixed it. This was definitely reproducible (though I only tried it with slashdot). Whenever I do this in Safari, Safari will reload the partially-loaded page automatically.