I (non-admin mode) was trying to post at a topic that still thought it was in the "Free For All" forum. This forum had since been renamed to "Free For All (No New Topics)".
The same name addition has recently been done to the "Welcome, Visitors!" forum, now known as the "Welcome, Visitors! (No New Topics)" forum.
If anyone has had problems getting messages posted to these forums, the name changes are probably the reason. I am currently executing a "Thread Update" for all forums, which should fix the problem (It did for the "FFA").
Cheers,
Adminnemooseus