Comment 6 for bug 1079283

It also happens on my system for files that are not in a Shotwell library (I don't use Shotwell and some files are text so shouldn't end up in Shotwell anyway).

To me, it seems the recently-used.xbel file is read, but not filtered. I've created a small Python script to filter the recently-used.xbel file according to the Zeitgeist blacklist - something like this ought to be implemented in the Dash.
https://dl.dropboxusercontent.com/u/278272/Linux/fix-recently-used.py