User blog comment:DaNASCAT/Technical Update: November 27, 2012/@comment-44043-20121128110135/@comment-1474707-20121128110639

I presume this was an attempt to fix the fact that link suggest previously obscured whatever you were typing (which was very annoying), but the implementation of the fix is pretty horrible - if you're typing near the bottom of the page the suggestions go down off the screen, and a second scrollbar appears on the page in order to scroll down to see all the suggestions