I was trying to add a usable tile in the planet screen with the Soil Enhancement project, but it failed to display any tiles for the project. Instead, it selected the tile that had the "colony capital" already built on it. It also failed to show the "soil enhancement" project as selected in the "available projects" list. A picture can be seen at https://www.dropbox.com/s/3l80ncltcwr7qz4/Screenshot 2015-04-01 15.43.21 soil enhancement bug.png?dl=0
This seems to be a random error as I have already built the soil enhancement on several other planets.
I have submitted a ticket for this issue.