I think I finally found out what really happened regarding the problem I mentioned in the other thread. The main culprit lies in modified PS document links.
When I create a link to a PS document within a PS document, the link will look like "http://index.php?...", a relative link. If I open that parent document again, do any modification and update it, the link will suddenly become an absolute link, looking like "http://my.domain.com/index.php...".
Not only is this not nice, it also creates not working links on the site in question, because the user account name is not included. Is there any way to get rid of this behaviour?