Fix issue where tribe header gets misplaced during large scroll

Platform: OS X Chrome 43 Stable.

Description: The tribe header can sometimes appear offset or in a flat out wrong location when doing large scrolls.

Steps to Reproduce:

1. Install a Chrome extension which allows for immediate scrolling to the top of the page, such as Vimium. Vimium will be used as an example for this bug report.

2. Browse to /t/gaming

3. Scroll down the page.

4. Use the "Scroll to the top of the page" feature of Vimium, which is bound to the "gg' keyboard command by default.

Expected Results

The tribe header returns to the top of the page.

Actual Results

The tribe header remains further down on the page, leaving a gap at the top where the header would be. Here is an image of the phenomenon.