I've had to add password protection to the SimpleLog Trac recently, due to craploads of spam. Almost every ticket was affected, almost every page was edited, it was a huge mess. I've tried to get everything back to normal (for the most part it is now), and I've added authentication.
From now on, you'll need to click the "login" link and log in with "anon" as the username and password. Then you'll be able to submit new tickets.