Did you kill any NPCs that were not hostile (like the friendly orcs in the catacombs) or get caught stealing?
When you use a statuette there is a brief delay before alignments change, so if you turn back into a human and immediately attack a normally hostile creature, they may still be friendly.
reputation decreased because of orcThere is a way to edit the displayed reputation value, but nobody has discovered exactly where the actual value is stored. I looked some time ago, but was unsuccessful... if my vague recollection is correct I may have determined the reputation is stored in the story.* files (which don't have any readable headers to help narrow down where things are, and when they are updated there is usually a lot of stuff added, deleted and/or changed).