The sub-forum collapse button seems to be opening the parent forum when you click on it. I would think that hitting the button would collapse the sub-forum list. On the main page, I scrolled to (ironically) Xenforo Bug Reports. I hover over the expander for sub-forums I click on the collapse button to collapse the list The parent (Xenforo Bug Reports) opens I would not think that this was by design. Using Windows 7 with IE8.