--- Games-Go-SimpleBoard/SimpleBoard.pm	2008/06/25 20:49:38	1.10
+++ Games-Go-SimpleBoard/SimpleBoard.pm	2008/07/23 19:19:31	1.12
@@ -102,6 +102,10 @@
    my $class = shift;
    my $size = shift;
 
+   unless ($size > 0) {
+      Carp::croak ("no board size given!");
+   }
+
    bless {
       max       => $size - 1,
       size      => $size,
@@ -313,7 +317,8 @@
 
    my $board = $self->{board};
 
-   return if $board->[$x][$y] & (MARK_B | MARK_W | MARK_KO);
+   return if $board->[$x][$y] & (MARK_B | MARK_W | MARK_KO)
+             && !($board->[$x][$y] & MARK_GRAYED);
 
    if ($may_suicide) {
       return 1;