I hope someone can perhaps shed some light on this, I'm currently waiting for a reply on a GM ticket.
I haven't been playing my warrior properly since the end of Cata, I can't remember doing the Bloodsail Grind on her, my reputations with the Steamweedle Cartel are at Revered from grinding through the game pre-cataclysm. Now that all of the quests have reset I can't help but think there has been a bug along the way.
I just went to show my friend about the nice spot to farm silk in southern stv just south of the arena, and while he can attack the enemies there, I can't. The mobs are friendly to me even though my reputation is hated. The At War box field is ticked and greyed out assuming I can't toggle it on or off. I've tried a fresh install without a UI installed tna. Has anyone else had a similar issue?
You might be on the quest where you can walk around safely. There is one or two out there where they are flagged as friendly for the duration.
I had the same issue when I was going to start my Insane business. It annoyed me so I went off and farmed the Lockboxes instead on my Rogue but it was only after checking wowhead I think that I realised I hadn't finished the quest line.
Go back to STV and finish it off, I believe the final battle is Booty Bay with some ship attacks if I recall correctly!