GridView scroll in Metro application doesn't work - xaml

Question

I trying to build a winRT metro application that use a GridView. I get the GridView and it looks like I want it to do. But the horizontal scroll doesn't work. When I drag the content it move but when I release it, it will return to start.
Anyone that know why it doesn't work?
<Page
x:Class="WR.Levels"
IsTabStop="false"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:Wordy"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:uc="using:Wordy.UserControls"
mc:Ignorable="d">
<UserControl.Resources>
<CollectionViewSource x:Name="cvsLevels" IsSourceGrouped="True"/>
<CollectionViewSource x:Name="cvsCategories" IsSourceGrouped="True" ItemsPath="Levels"/>
</UserControl.Resources>
<Canvas x:Name="innertialCanvas"
Grid.Row="1"
Background="#FF3D6E4F"
>
<uc:BG HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="84"/>
<RowDefinition Height="700"/>
</Grid.RowDefinitions>
<StackPanel Margin="20,20,0,0" Grid.Row="0" Orientation="Horizontal">
<Button x:Name="backButton" Style="{StaticResource BackButtonStyle}" Margin="10" VerticalAlignment="Center" >Back</Button>
<TextBlock Name="appName" Text="WR" FontSize="48" VerticalAlignment="Center" />
</StackPanel>
<GridView ItemsSource="{Binding Source={StaticResource cvsCategories}}" Margin="0,0,0,0"
IsItemClickEnabled="True" SelectionMode="None" MaxHeight="700" Grid.Row="1"
AutomationProperties.AutomationId="LevelsGrid">
<GridView.ItemTemplate>
<DataTemplate>
<StackPanel Width="150" Height="130" Margin="10" AutomationProperties.AutomationId="Level">
<StackPanel.Background>
<SolidColorBrush Color="White" Opacity="0.2" />
</StackPanel.Background>
<StackPanel Orientation="Horizontal" Margin="10">
<uc:Stars Height="50" Width="50" />
<uc:Stars Height="50" Width="50" />
</StackPanel>
<TextBlock Text="{Binding Name}" Margin="0,10,0,0" FontSize="24" HorizontalAlignment="Center"></TextBlock>
</StackPanel>
</DataTemplate>
</GridView.ItemTemplate>
<GridView.ItemsPanel>
<ItemsPanelTemplate>
<VirtualizingStackPanel Orientation="Horizontal"/>
</ItemsPanelTemplate>
</GridView.ItemsPanel>
<GridView.GroupStyle>
<GroupStyle HidesIfEmpty="True">
<GroupStyle.HeaderTemplate>
<DataTemplate>
<Grid Margin="0">
<TextBlock Text='{Binding Name}'
Foreground="White" Margin="20"
Style="{StaticResource HeaderTextStyle}" AutomationProperties.AutomationId="LevelGroup"/>
</Grid>
</DataTemplate>
</GroupStyle.HeaderTemplate>
<GroupStyle.ContainerStyle>
<Style TargetType="GroupItem">
<Setter Property="Margin" Value="3,0"/>
</Style>
</GroupStyle.ContainerStyle>
<GroupStyle.Panel>
<ItemsPanelTemplate>
<VariableSizedWrapGrid/>
</ItemsPanelTemplate>
</GroupStyle.Panel>
</GroupStyle>
</GridView.GroupStyle>
</GridView>
</Grid>
</Canvas>
</Page>

Answer 1

When I removed the canvas tag it worked!