For certain websites -- but not all -- the saved snapshots (such as to the link at bottom of this post) of certain web pages are only showing up as partial snapshots when I open them. The top part of the snapshot is blacked out in an area equal roughly to the size of my screen less the size of the zotero box. Any clues? Thanks.

Example:
http://oi.uchicago.edu/research/library/dissertation/proposals/hansen.html