I'm not sure that the mods know how to update a title thread. What you did only changed the post's title. To change the title of a thread go to the subforum a thread was made in (in this case, that means going to the Suggestions forum:
http://www.wyvernrpg.com/forum/forumdisplay.php?f=7). Then double click the on the thread's title.
Either you, as a regular user, or a mod
should be able to do this, but I've never attempted it on a non-admin account, so I'm not absolutely certain.