During the 2nd invasion of the keep, my party member killed a hireling that was charmed. After that, every single hireling I hire turns hostile on sight. I dismissed all and rehired, still hostile. Went out did some quests, came back, still hostile........

 

Searched around the net, it seems many people has this problem. But it is not reported here.

I also have this problem. Wouldn't be such a big deal, just means I feel like its a wasted opportunity whenever a special hireling comes to the Stronghold.

Just had the same problem. I tried the battle twice more and they were not charmed on the last time. I used the priest spell "prayer against treachery".