Firnwind

In the first attack on Caed Nua I also hit some of my own hired guards with spells and they got hostile. So far so bad, I naturally killed them all and went on. But now I have the problem that, whenever I visit Caed Nua all of my hired guards outside the buildings are hostile and attack on sight. I fired all guards, left the keep, hired new ones but the problem persists which make any visit to Caed Nua very tiresome ... is there any way to reset this or do something about it?