This is a great error!
I've been trying to reproduce this one many times, but was never able to do so...
It basically means that the program is trying to open a file, thinks it is an image file that is not a jpeg neither a gif. By default it then assumes the image is a png file, which it is probably not.
It's probably a problem in some string...
Maybe (not sure) you are missing the "momir basic" deck in Res/Player.
It can be found here:http://wagic.googlecode.com/svn/trunk/p ... /momir.txt
if putting this file in Res/Player does not solve the issue, please let me know.
I would love to know how to reproduce this one!