On the O'Reilly page at http://www.checkio.org/station/oreilly/

Before you unlock the other 3 stations, there are images for each at the top of the challenge list. Directly below the text: "Collect points to unlock new stations"

The missing image's URL is: http://www.checkio.org/static/imgv3/stations/codeship/locked.png

Just wanted to pass this along to checkio staff so that it can be corrected.

Edited to Add: This image url is also coming up 404: http://www.checkio.org/static/imgv3/stations/codeship/unlocked.png