TEAMBUILD: error MSB4057: The target "GetXapOutputFile" does not exist in the project

Question

I'm getting this error trying to run my Build thru TeamBuild in TeamExplorer on Visual Studio 2008.

On the Build Machine I installed VS SP1, Team Explorer, Silverlight 3 tools, and RIA Services.

I can compile no problem with Visual Studio on my machine and directly on the Build Machine. But I still cant compile on thru TeamBuild because it "says" I'm missing GetXapOutputFile target.

I checked C:\Program Files\MSBuild\Microsoft\Silverlight\v3.0\Microsoft.Silverlight.Common.targets file and it does have the GetXapOutputFile target:

<!--
============================================================
                        GetXapOutputFile

This stand-alone target returns the name of the built xap file.It
only makes sense to call this after a build
============================================================
-->
<Target
    Name="GetXapOutputFile"
    DependsOnTargets="_CreateSLProperties" 
    Outputs="$(XapOutputFile)"
/>

Any idea what I might be missing?