(You can skip to step 2)

1. Find a diff: eg: https://secure.phabricator.com/rP3c6c6552d34b53d40c30100701fcf85c140c440c
2. Click on one of the files in the list eg: https://secure.phabricator.com/rP3c6c6552d34b53d40c30100701fcf85c140c440c#a1890f65
3. you are moved to the anchor position
4. scroll and then hover over "View Options" or try and click on a button
5. ?????
6. you get scrolled to the anchor

Screencast: http://screencast.com/t/2zsjz2gck

This may be a duplicate of that other chrome one