It is showing for me as well. I don’t believe any of the profile settings we have will impact this, do you have any ad block plugins loaded? Sometimes they will wrongly detect if something is an ad and block the element.
I zoomed in a whole bunch in my Firefox until I couldn't see the rare achievements. Pressing End on my keyboard showed me they are still there at the bottom, below the recent games list. Of course Exophase wants to load older recent games when you scroll down, so scrolling up a little bit makes them drop down and out of sight again.
Maybe the site should have the rare achievements above everything else in the code? They could still be displayed on the right on higher resolutions, and on lower resolutions they would be properly viewable near the top.