I've come to a more precise description of the bug: Whenever foreign dead
stones are within an area the whole area is not counted. My version is
gnugo 3.8, I've downloaded it from http://gnugo.baduk.org/ today. I use the
graphical interface Panda. My operating system is Windows XP. Maybe this is
of help for you. Please inform me how I can fix the bug or send me a
repaired version of the gnugo 3.8 binaries for Windows. Many thanks