[gbrainy] Fixes exception when changing difficulty level in custom game list

[Jordi Mas <jmas src gnome org>]

commit 2cd2ce2e292880ed80686c13212a80b42c28243e
Author: Jordi Mas <jmas softcatala org>
Date:   Sat Jul 24 08:36:46 2010 +0200

    Fixes exception when changing difficulty level in custom game list

 src/Core/Main/GameManager.cs |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)
---
diff --git a/src/Core/Main/GameManager.cs b/src/Core/Main/GameManager.cs
index d302408..9f22a51 100644
--- a/src/Core/Main/GameManager.cs
+++ b/src/Core/Main/GameManager.cs
@@ -126,7 +126,9 @@ namespace gbrainy.Core.Main
 					return;
 
 				difficulty = value;
-				BuildPlayList (available_games);
+
+				if ((game_type & GameSession.Types.Custom) != GameSession.Types.Custom)
+					BuildPlayList (available_games);
 			}
 			get { return difficulty; }
 		}