If you used Fileinfo Peeper 2.0, you must convert "Fileinfo Peeper preferences" file to use 2.1 or newer safely. To do so, please please download Fileinfo Converter from my website,
http://www01.u-page.so-net.ne.jp/jd5/ichiuma/
If you don't want to download, drop "Fileinfo Peeper Preferences" to the Trash.
But, in this case, new Fileinfo Peeper can't take over the preferences of the previous version.