I have stopped using this plugin as there are far better and more flexible solutions for using chess games or diagrams in WordPress blogs. You could try:
The Chessflash PGN Viewer is a very nice and easy way to display chessgames on a website. I wrote a simple plugin which makes the use in WordPress blogs really easy: just type [ pgn][ /pgn] and place the pgn-data in between the tags.
You can download the plugin from the WordPress Plugin Directory (chessflash.swf version 2.16 is included with a different piece set than the original from chessflash.com). Just unzip and copy the wp-chessflash directory in you wordpress plugins directory and activate the plugin via wordpress dashboard.
It’s my first plugin, so there might be some silly bugs 😉
Colors and piece characters can be set in the options page in the WordPress ‘Settings’ menu. Usage is explained in the readme.txt in the zip-file.
23-11-2014: problem in WordPress 4.0.1
The last WordPress update has caused a problem with the plugin. I hope to fix this soon.
24-11-2014: fixed some bugs that were causing the problems. Current version is 1.2