EDIT: It seems that ListPicker is the way to go but I have had further problems with that detailed Microsoft.Phone.Controls.Toolkit ListPicker throws XamlParseException

I have the following ComboBox in code:

<ComboBox x:Name="Result" Grid.Column="6" HorizontalAlignment="Center" VerticalAlignment="Center" Foreground="Black" Background="White">   
    <ComboBoxItem Content="Win" />  
    <ComboBoxItem Content="Place" />  
    <ComboBoxItem Content="Lose" />  
</ComboBox> 

But it does not display as I would have expected. When you drop down the ComboBox the options don't appear, it's just like empty items. See below:

However, when an item is selected, it displays correctly and the correct index/item is returned. See below:

I'm sure there is something simple I have missed but can't put my finger on it.

EDIT: Ok I am posting the full code for this. I have a user control, OddsRow, that looks like this:

<UserControl xmlns:toolkit="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone.Controls.Toolkit"  x:Class="MojoPinBetOddsCalculator.OddsRow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    FontFamily="{StaticResource PhoneFontFamilyNormal}"
    FontSize="{StaticResource PhoneFontSizeNormal}"
    Foreground="{StaticResource PhoneForegroundBrush}"
    d:DesignHeight="480" d:DesignWidth="480">

    <Grid x:Name="LayoutRoot" Background="{StaticResource PhoneChromeBrush}">
        <Grid.RowDefinitions>
            <RowDefinition Height="70"/>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="50*"></ColumnDefinition>
            <ColumnDefinition Width="70*"></ColumnDefinition>
            <ColumnDefinition Width="30*"></ColumnDefinition>
            <ColumnDefinition Width="70*"></ColumnDefinition>
            <ColumnDefinition Width="70*"></ColumnDefinition>
            <ColumnDefinition Width="70*" ></ColumnDefinition>
            <ColumnDefinition Width="100*"></ColumnDefinition>
        </Grid.ColumnDefinitions>
        <TextBlock x:Name="RowNumber" Grid.Column="0" VerticalAlignment="Center" HorizontalAlignment="Center"></TextBlock>
        <TextBox x:Name="OddsNumerator" Grid.Column="1" Width="90" Height="70" HorizontalAlignment="Center" TextAlignment="Center" VerticalAlignment="Center" MaxLength="3" InputScope="TelephoneNumber"></TextBox>
        <TextBlock x:Name="Slash" Grid.Column="2" Text="/" HorizontalAlignment="Center" VerticalAlignment="Center"></TextBlock>
        <TextBox x:Name="OddsDenominator" Grid.Column="3" Width="90" Height="70" VerticalAlignment="Center" TextAlignment="Center" MaxLength="3" HorizontalAlignment="Center" InputScope="TelephoneNumber"></TextBox>
        <CheckBox x:Name="EachWay" Grid.Column="4" VerticalAlignment="Center" HorizontalAlignment="Center" Margin="10,0,0,0" />
        <CheckBox x:Name="Place" Grid.Column="5" HorizontalAlignment="Center" VerticalAlignment="Center" BorderThickness="0" Width="71" Margin="10,0,0,0" Padding="0" />
        <ComboBox x:Name="Result" Grid.Column="6" HorizontalAlignment="Center" VerticalAlignment="Center" Foreground="Black" Background="White">
            <ComboBoxItem Content="Win" />
            <ComboBoxItem Content="Place" />
            <ComboBoxItem Content="Lose" />
        </ComboBox>
    </Grid>
</UserControl>

And it is displayed in the MainPage like so:

<phone:PhoneApplicationPage xmlns:my="clr-namespace:MojoPinBetOddsCalculator"  
    x:Class="MojoPinBetOddsCalculator.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
    xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d" d:DesignWidth="480" d:DesignHeight="768"
    FontFamily="{StaticResource PhoneFontFamilyNormal}"
    FontSize="{StaticResource PhoneFontSizeNormal}"
    Foreground="{StaticResource PhoneForegroundBrush}"
    SupportedOrientations="Portrait" Orientation="Portrait"
    shell:SystemTray.IsVisible="True">

    <!--LayoutRoot is the root grid where all page content is placed-->
    <Grid x:Name="LayoutRoot" Background="Transparent">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>

        <!--TitlePanel contains the name of the application and page title-->
        <StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28">
            <TextBlock x:Name="ApplicationTitle" Text="BET ODDS CALCULATOR" Style="{StaticResource PhoneTextNormalStyle}"/>
            <TextBlock x:Name="PageTitle" Text="calculate" Margin="9,-7,0,0" Style="{StaticResource PhoneTextTitle1Style}"/>
        </StackPanel>
        <!--ContentPanel - place additional content here-->
        <Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0" HorizontalAlignment="Stretch">
            <Grid x:Name="Scrollable">
                <ScrollViewer>
                <Grid x:Name="BettingGrid">
                    <Grid.RowDefinitions>
                        <RowDefinition Height="Auto"></RowDefinition>
                        <RowDefinition Height="*"></RowDefinition>
                    </Grid.RowDefinitions>
                    <Grid x:Name="BetList">
                        <Grid.RowDefinitions>
                            <RowDefinition Height="30"></RowDefinition>
                            <RowDefinition Height="70"></RowDefinition>
                            <RowDefinition Height="70"></RowDefinition>
                            <RowDefinition Height="70"></RowDefinition>
                            <RowDefinition Height="70"></RowDefinition>
                            <RowDefinition Height="70"></RowDefinition>
                            <RowDefinition Height="70"></RowDefinition>
                        </Grid.RowDefinitions>
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="50*"></ColumnDefinition>
                            <ColumnDefinition Width="70*"></ColumnDefinition>
                            <ColumnDefinition Width="30*"></ColumnDefinition>
                            <ColumnDefinition Width="70*"></ColumnDefinition>
                            <ColumnDefinition Width="70*"></ColumnDefinition>
                            <ColumnDefinition Width="70*"></ColumnDefinition>
                            <ColumnDefinition Width="100*"></ColumnDefinition>
                        </Grid.ColumnDefinitions>
                        <TextBlock Text="EW"  Style="{StaticResource PhoneTextNormalStyle}" Grid.Row="0" Grid.Column="4" HorizontalAlignment="Center" />
                        <TextBlock Text="Place"  Style="{StaticResource PhoneTextNormalStyle}" Grid.Row="0" Grid.Column="5" HorizontalAlignment="Center" />
                        <TextBlock Text="Result"  Style="{StaticResource PhoneTextNormalStyle}" Grid.Row="0" Grid.Column="6" HorizontalAlignment="Center" />
                        <my:OddsRow Grid.Row="1" Grid.ColumnSpan="7" Row="1"/>
                        <my:OddsRow Grid.Row="2" Grid.ColumnSpan="7" Row="2"/>
                        <my:OddsRow Grid.Row="3" Grid.ColumnSpan="7" Row="3"/>
                        <my:OddsRow Grid.Row="4" Grid.ColumnSpan="7" Row="4"/>
                        <my:OddsRow Grid.Row="5" Grid.ColumnSpan="7" Row="5"/>
                        <my:OddsRow Grid.Row="6" Grid.ColumnSpan="7" Row="6"/>
                    </Grid>
                    <Grid x:Name="ControlsGrid" Grid.Row="1">
                        <Button x:Name="AddRowButton" Background="#BFFFFFFF" BorderBrush="#BFFFFFFF" Foreground="Black" Content="Add Row" FontSize="16" Click="AddRowButton_Click" Height="70" />
                    </Grid>
                </Grid>
                </ScrollViewer>
            </Grid>
        </Grid>
    </Grid>
</phone:PhoneApplicationPage>

Separately the ComboBox works, and also the code for the OddsRow works as expected... separately. When combined it doesn't display the items.

OddsRow.xaml.cs

public partial class OddsRow : UserControl
{
    private int m_Row;

    public OddsRow()
    {
        InitializeComponent();
    }

    public int Row
    {
        get
        {
            return m_Row;
        }
        set
        {
            m_Row = value;
            RowNumber.Text = m_Row + " - ";
        }
    }
}