Created Issue: LongListSelector can‘t Binding data to IsFlatList [10603]

The Code is
<toolkit:LongListSelector x:Name="SongsList"
ItemsSource="{Binding Source={StaticResource Locator}, Path=MainMusic.SongItems.Items}" Background="Transparent"
IsFlatList="{Binding Source={StaticResource Locator}, Path=MainMusic.SongItems.IsMini}"
ItemTemplate="{StaticResource SongItemTmpl}"
GroupHeaderTemplate="{StaticResource GroupHeader}"
GroupItemTemplate="{StaticResource GroupItem}"
GroupViewClosing="citiesListGropus_GroupViewClosing"
GroupViewOpened="citiesListGropus_GroupViewOpened">
<toolkit:LongListSelector.GroupItemsPanel>
<ItemsPanelTemplate>
<toolkit:WrapPanel Orientation="Horizontal"/>
</ItemsPanelTemplate>
</toolkit:LongListSelector.GroupItemsPanel>
</toolkit:LongListSelector>
the error message is
"Set property 'Microsoft.Phone.Controls.LongListSelector.IsFlatList' threw an exception. [Line: 182 Position: 47]".


I'm sure that the data I binding is True.
even if I change the property IsFlatList in the codebehind,it didn't work!