:include not working

I have one model User. And i have used acts_as_commentable_with_threading plugin. I am firing query @comments = Comment.find(:all,:include => :user) it generate mysql properly. SELECT SQL_NO_CACHE * FROM `comments` SELECT SQL_NO_CACHE * FROM `users` WHERE (`users`.`id` IN (1,4,5)) .

But when i am using comment.user in my partial file it's firing query again. I don't know why this problem is occurring.

Anyone can help me.