This time I'm using an evil party. (Me, Kagain, Viconia, Montaron & Xzar)
Currently my reputation is 4 by the time I was heading to Nashkel. =)
So, apparently, at that stage all the Nashkel Guards turn hostile and start attacking me the minute I enter Nashkel. I killed them all, sending my rep to the abyss. Then I reloaded and went to the temple to up my reputation.
But, and here's the problem, no matter how much I donate, I cannot increase my reputation and it stays at 4. Anyone knows exactly how to raise reputation?