DateTime Data Problems in Silverlight and C#

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DateTime Data Problems in Silverlight and C#
Hello Forum.
I am using VISI Fire in Silverlight and C# to produce some data charts. One style of chart allows stacked data to be displayed in colums the xaml code I am using looks like this

The chart i am trying to build is based on a visi fire chart example. if you go to Silverlight, WPF, ASP.Net Charts & Gauges Gallery and look at their stacked examples here Silverlight Stacked Charts Gallery you can see the xaml example I am trying to emulate.
[ame]http://i67.photobucket.com/albums/h292/Athono/post_this.png[/ame]
But my chart comes out differently. mine has this odd overlaping date feature

Now, I have carefully stepped through the code and as far as I can tell, I have the same date for each data set pair.

I have stepped through this code and I have made sure that with each value for i, the years and the months for each data pair are exactly the same. So why is my graph so messed up?
Is there something wrong with they way I am using the DateTime class?
new DateTime((Int32) Year_Id,(Int32) SMonth_Id, (Int32)1);

 

[Complete]

I fixed this.

<vc:Chart.AxesX>
<vc:Axis ValueFormatString="MMM - yyyy" Padding="4" LineThickness="0" IntervalType="Months" Interval="1"/>

</vc:Chart.AxesX>