That is set when you create a new forum or section....
Go to...
Forums and Posts -> Forum Management -> (EDIT OR ADD NEW) -> Additional Forum options -> Moderation options...
There you can set if new threads/posts should be put into mod log...
Go to...
Forums and Posts -> Forum Management -> (EDIT OR ADD NEW) -> Additional Forum options -> Moderation options...
There you can set if new threads/posts should be put into mod log...