Arena Glitched

Without knowing anything about your load order, but knowing that you are using older Morroblivion Mods instead of the new master, I would be willing to bet the problem is CNME. CNME is one of the dirtiest mods I have ever seen. It edits Hundreds of Vanilla Oblivion scripts that it has no business touching, including ArenaAggressionScript, ArenaAnouncerScript, and a total of 42 Arean-related scripts. I cannot recommend using CNME for that reason. Most of the older Morroblivion mods I have looked at have been very dirty. You should be careful with what you use because a fair number of the early Morroblivion modders obviously were not.

CNME is CoolShady/NickV's mod. It was one of the staple Morroblivion mods in days past. This is not Nexus; there aren't a bunch of people hanging around that can spot problems with Load Order just by looking. I know I'm not going to look through it. CNME was my only guess, but as I said, MOST Morroblivion mods I have looked at have been very dirty, so it could be any of them. Sorry, but I think you're mostly on your own here. Just start didabling one at a time until you find the culprit.