PHP Manual problems

Recently I have frequently found, especially in the morning (GMT 2200 - 0200), that I can open a bookmark in the manual, for example http://www.php.net/manual/en/ref.image.php. But if I then do a search of any type I get 'The page cannot be displayed'. I then cannot reach any page, including the one I originally opened. This morning, after some fiddling, I found that if I closed the browser, and re-opened it I could then see the original bookmark again, and link to some pages, but others would again crash the browser, as would all searches. I am using IE6, and have seen a message that I should update my browser, but only when the page is displaying properly. Firefox 3.5.5 immediately converted the above to http://au2.php.net/manual/en/ref.image.php. and then told me "The manual page you are looking for (http://au2.php.net/manual/en/ref.image.php.) is not available on this server right now." Is this due to maintenance, or somesuch, or is it something in my system?