wp8 listbox scrolling doesn't work - xaml

Question

I have list box in my WP8 and I can't scroll to down.When I try to scroll down the whole list moves to down .I dont know how to explain it but it does what it shouldn't do. it is like i drag list down.i just want to scroll
here is my xaml code
<Grid x:Name="columngrid" >
<ListBox Name="URLListBox" >
<ListBox.ItemTemplate>
<DataTemplate>
<Grid Background="Transparent" Margin="0,0,0,3" >
<Grid.ColumnDefinitions>
<ColumnDefinition Width="170"/>
<ColumnDefinition Width="100"/>
<ColumnDefinition Width="100"></ColumnDefinition>
<ColumnDefinition Width="100"></ColumnDefinition>
</Grid.ColumnDefinitions>
<TextBlock x:Name="surename" Grid.Column="0" Text="{Binding text}" TextWrapping="Wrap" VerticalAlignment="Center" HorizontalAlignment="Center"/>
<Button Tag="{Binding b1Tag}" Grid.Column="1" Content="download" Height="72" Name="button1" Width="100" FontSize="15" Click="addButton_Click"/>
<Button Tag="{Binding b1Tag}" Grid.Column="2" Content="play" Height="72" Name="play_Click" Width="100" FontSize="15" Click="play_Click"/>
<Button Tag="{Binding b1Tag}" Grid.Column="3" Content="pause" Height="72" Name="pause_Click" Width="100" FontSize="15" Click="pause_Click"/>
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</Grid>

Answer 1

I think the problem is that your listbox is sizing to the content.
When this happens it wont scroll when you attempt to scroll it. It will follow your finger slightly, then bounce back to the top.
In reality what is happening is the listbox is the same size as all the content so it thinks you're at the bottom of the list.
The way to fix this is to manually set the size of the listbox to be the dimensions of the screen.
Something like Margin="0,0,0,0" width="480" height="800"