主题：[求助]列标题设置失效

有一个产品信息表，想让不同的用户组登录时，列标题动态改变，代码如下：

With DataTables("产品信息")
    Dim nmms() As String ={"电雕在制支数","机加在制支数","镀铜在制支数","车研在制支数","镀铬在制支数","料库在制支数","打样在制支数","印前在制支数","总检在制支数"}
    Dim nms() As String = {"电雕在制明细","机加在制明细","镀铜在制明细","车研在制明细","镀铬在制明细","料库在制明细","打样在制明细","印前在制明细","总检在制明细"}
    If _UserGroup <> "生产部" Then
        For Each nmm As String In nmms
            .DataCols(nmm).Caption = "在制支数"
            For Each nm As String In nms
                .DataCols(nm).Caption = "明细"
            Next
        Next
    Else

        For Each nmm As String In nmms
            .DataCols(nmm).Caption = Nothing
            For Each nm As String In nms
                .DataCols(nm).Caption = Nothing
            Next
        Next
    End If
End With

现在的问题是我以生产部登录时，列标题还是“在制支数”和“明细”，这是为什么？