设置DataLoadOptions时，LINQ返回错误的项数

下面是一个代码示例:

MyDataContext context = new MyDataContext();
Symbol symbol = (from s in context.Symbols where s.ID = 3257 select s).First();
ProtocolVariable[] variables = symbol.ProtocolVariables.ToArray();    
context.Dispose();

使用调试器，我看到变量的数量等于3(变量)。长度== 3)。现在我稍微改变一下代码:

MyDataContext context = new MyDataContext();
DataLoadOptions dlo = new dataLoadOptions();
dlo.LoadWith<Symbol>(s => s.ProtocolVariables);
context.LoadOptions = dlo;
Symbol symbol = (from s in context.Symbols where s.ID = 3257 select s).First();
ProtocolVariable[] variables = symbol.ProtocolVariables.ToArray();    
Context.Dispose();

调试器现在显示变量的数量等于1。

这怎么可能?

这里是一些附加信息(我不知道它是否重要):

• "符号"是一个表
• 协议变量是一个视图
• "Symbols"answers"ProtocolVariables"的关联，我用*添加。dbml文件。

下面是第一个代码示例后面的SQL查询:

SELECT 
[t0].[ID], 
[t0].[SubsystemID], 
[t0].[GenericName], 
[t0].[LocalName], 
[t0].[TypeID], 
[t0].[Array], 
[t0].[Array2], 
[t0].[UnitID], 
[t0].[Description], 
[t0].[ProtocolID]
FROM [dbo].[Symbols] AS [t0]
WHERE [t0].[ID] = 3257

SELECT 
[t0].[ID], 
[t0].[SubsystemID], 
[t0].[GenericName], 
[t0].[LocalName], 
[t0].[TypeID], 
[t0].[Array], 
[t0].[Array2], 
[t0].[UnitID], 
[t0].[Description], 
[t0].[ProtocolID], 
[t1].[ID] AS [ID2], 
[t1].[SymbolID], 
[t1].[SubsystemID] AS [SubsystemID2], 
[t1].[GenericName] AS [GenericName2], 
[t1].[LocalName] AS [LocalName2], 
[t1].[TypeID] AS [TypeID2], 
[t1].[Array] AS [Array3], 
[t1].[Array2] AS [Array22], 
[t1].[UnitID] AS [UnitID2], 
[t1].[Description] AS [Description2], 
[t1].[ProtocolID] AS [ProtocolID2], 
[t1].[VariableTypeID], 
(
    SELECT COUNT(*)
    FROM [dbo].[ProtocolVariables] AS [t2]
    WHERE [t2].[SymbolID] = [t0].[ID]
    ) AS [value]
FROM [dbo].[Symbols] AS [t0]
LEFT OUTER JOIN [dbo].[ProtocolVariables] AS [t1] ON [t1].[SymbolID] = [t0].[ID]
WHERE [t0].[ID] = 3257
ORDER BY [t0].[ID], [t1].[ID]