Thanks, Victor! That did fix the errors I was receiving. However, I'm still having trouble getting the sample to work, using even the simplest code from the help docs. I don't expect to see info, but shouldn't I be seeing a TrackBallControl with the code below?
<phone:PhoneApplicationPage
x:Class="TelerikWindowsPhoneApp1.MainPage"
xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
mc:Ignorable="d"
xmlns:telerikChart="clr-namespace:Telerik.Windows.Controls;assembly=Telerik.Windows.Controls.Chart"
xmlns:telerikChartEngine="clr-namespace:Telerik.Charting;assembly=Telerik.Windows.Controls.Chart"
xmlns:telerikChartSpecialized="clr-namespace:Telerik.Windows.Controls.Chart;assembly=Telerik.Windows.Controls.Chart"
xmlns:local="clr-namespace:TelerikWindowsPhoneApp1"
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="MY APPLICATION" Style="{StaticResource PhoneTextNormalStyle}"/>
<TextBlock x:Name="PageTitle" Text="page name" 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">
<telerikChart:RadCartesianChart>
<telerikChart:RadCartesianChart.Behaviors>
<telerikChart:ChartTrackBallBehavior ShowIntersectionPoints="True"
ShowTrackInfo="False" />
</telerikChart:RadCartesianChart.Behaviors>
<telerikChart:RadCartesianChart.HorizontalAxis>
<telerikChart:LinearAxis />
</telerikChart:RadCartesianChart.HorizontalAxis>
<telerikChart:RadCartesianChart.VerticalAxis>
<telerikChart:LinearAxis />
</telerikChart:RadCartesianChart.VerticalAxis>
<telerikChart:ScatterLineSeries>
<telerikChart:ScatterLineSeries.TrackBallTemplate>
<DataTemplate>
<Rectangle Width="20" Height="20"
Fill="{StaticResource PhoneForegroundBrush}"
RenderTransformOrigin="0.5,0.5">
<Rectangle.RenderTransform>
<RotateTransform Angle="45" />
</Rectangle.RenderTransform>
</Rectangle>
</DataTemplate>
</telerikChart:ScatterLineSeries.TrackBallTemplate>
<telerikChartEngine:ScatterDataPoint XValue="5" YValue="5" />
<telerikChartEngine:ScatterDataPoint XValue="15" YValue="5" />
<telerikChartEngine:ScatterDataPoint XValue="20" YValue="5" />
</telerikChart:ScatterLineSeries>
</telerikChart:RadCartesianChart>
</Grid>
</Grid>
</phone:PhoneApplicationPage>