diff -r d37db4dcc88d -r 1560c419b176 userlibandfileserver/fileserver/sfat32/inc/sl_std.inl
--- a/userlibandfileserver/fileserver/sfat32/inc/sl_std.inl	Tue Aug 24 14:49:21 2010 +0100
+++ b/userlibandfileserver/fileserver/sfat32/inc/sl_std.inl	Tue Aug 31 11:31:15 2010 +0100
@@ -645,6 +645,16 @@
     }
 
 
+//-----------------------------------------------------------------------------
+/**
+    @return ETrue if the cluster number aClusterNo is valid, i.e. belongs to the FAT table
+*/
+inline TBool CFatTable::ClusterNumberValid(TUint32 aClusterNo) const 
+    {
+    return (aClusterNo >= KFatFirstSearchCluster) && (aClusterNo < iMaxEntries); 
+    }
+
+
 /**
 @return Maximal number of addresable FAT entries. This value is taken from the owning mount
 */