Due to spam problems, I've changed the website long ago to require a login to create wiki pages or tickets or to modify them.

Probably this isn't obvious if somebody comes to the website to enter a ticket without reading the IssueTracker page first (which is very likely). As I want to make it really easy to enter or modify a ticket while at the same time keeping out spambots, the use of the ticket system should be made obvious, i. e. the usability of the site in this regard needs improving.

The problem is similar for the wiki pages. Here, the matter is even a bit more complicated because some pages (namely the home page, the release documentation and the download page) are read-only. If someone sees that they don't get an "Edit" button after logging in they'll probably conclude that the wiki generally isn't modifiable.