EDIT: I found the problem. when I was surfing through the WordPress Forum Someone post the similar problem and the cause is there’s an unwanted set of <div> tag around the post and I found it on the Code Geass Ep 7~ I delete them and Voila~ back to normal.
If you’re wondering why I change my layout, it’s because somehow the last digg theme was in a mess. Somehow the right bar moved to the bottom of page.
I already try some other theme, but also had some layout problems, only this one looks decent. So until I found a solution, please bear with this.