Actually, I tested your code sample with little modifications:

<Grid x:Name="LayoutRoot" Background="White">
 <ItemsControl x:Name="list" Height="300" Width="300" Background="Pink" >
  <ItemsControl.ItemTemplate>
   <DataTemplate>
    <igGauge:XamWebRadialGauge Height="100" Width="100">
     <igGauge:XamWebRadialGauge.Scales>
      <igGauge:RadialGaugeScale StartValue="{Binding StartValue}" EndValue="{Binding EndValue}">
       <igGauge:RadialGaugeScale.LabelGroups>
        <igGauge:RadialGaugeLabelGroup />
       </igGauge:RadialGaugeScale.LabelGroups>
      </igGauge:RadialGaugeScale>
     </igGauge:XamWebRadialGauge.Scales>
    </igGauge:XamWebRadialGauge>
   </DataTemplate>
  </ItemsControl.ItemTemplate>
 </ItemsControl>
</Grid>

public TestGauge()
{
       InitializeComponent();
       list.ItemsSource = new MyData();
}
public class MyData : ObservableCollection<Widget>
{
 public MyData(): base()
 {
  this.Add(new Widget() { StartValue = 1, EndValue = 2 });
  this.Add(new Widget() { StartValue = 3, EndValue = 4 });
  this.Add(new Widget() { StartValue = 5, EndValue = 6 });
 }
}
public class Widget
{
 public double StartValue { get; set; }
 public double EndValue { get; set; }
}

 i got this error, and even with your original sample:

AG_E_PARSER_BAD_PROPERTY_VALUE

Are you able tou reproduce it? or i missed a thing ?Help me...

Thanks a lot.

i found why...

Actually i worked on the 2009.1 version, and this bug was fixed in the last release 2009.2.

Thank you david!

it worked okay for me.  i have attached the sample project.

does the parser error point to a particular line number?