I have jimpeel's experience. Clicking bevtech's "online documentation" link takes me to: http://www.uvnc.com/index.html
which is just ultravnc's home page.
Next, going to this URL UltraVNC documentation website
and clicking Oliver's link labeled http://doc.ultravnc.net/
takes you here instead: http://www.uvnc.com/man/
-- The link may read http://doc.ultravnc.net/
but that's not where you end up by clicking it.
Furthermore, going to this URL: http://www.uvnc.com/man/
takes me to a practically empty page with the single word "Tutorials" in rather small font. This happens in Firefox, Opera and IE.
All this has convinced me that I don't even want to try UltraVNC. Keep working on it; maybe by the 22nd century you'll have links that work right.