I was updating my gnome installation and during the installation of gdk-pixbuf I ran out of diskspace on my /usr partition. The update stopped as I would have expected, but then after clearing up some space I reran my update command and noticed that portage began w/ the next package. I feel it should have rebuilt / reinstalled the previous ( gdk-pixbuf ) so that all files for that package where installed before moving on.
*** This bug has been marked as a duplicate of 10377 ***