Until recently all users had access to some surveys in one of my sites. Suddenly their rights were revoked. I assumed someone had removed them accidentally (an issue for another time), so I added them back in. To my surprise 15 minutes later the users had been removed once again. This happens every time.
This leads me to another (related) question. I have set up site collection auditing to find out whats happening, however it only shows that something was changed, not who changed it.
Any help is greatly appreciated.