MSBuild task: 'ItemGroup' has invalid child element 'SolutionFiles'

Hi,

In a .proj file I have specified a "SolutionFiles" element to the "ItemGroup" element. I got the info fromhere. And it works - but VS2010 complains that the element isn't in the definition. I get this warning:

Warning 1 The element 'ItemGroup' in namespace 'http://schemas.microsoft.com/developer/msbuild/2003' has invalid child element 'SolutionFiles' in namespace 'http://schemas.microsoft.com/developer/msbuild/2003'.

I would very much like to get rid of that. Is it a problem with the xmlns url or is it really not a supported element? What I'm doing is to include a file in the build output like this:

<?xmlversion="1.0"encoding="utf-8"?><Projectxmlns="http://schemas.microsoft.com/developer/msbuild/2003"><ItemGroup><SolutionFilesInclude="Repository.cmd"/><DocumentationFilesInclude="..\Documentation\*.*"/><LibFilesInclude="..\Lib\*.*;"/><ToolsFilesInclude="..\Tools\*.*;"/></ItemGroup><TargetName="CopyFiles"><CopySourceFiles="@(SolutionFiles)"DestinationFolder="$(OutDir)"/><CopySourceFiles="@(DocumentationFiles)"DestinationFolder="$(OutDir)\Deploy\Documentation"/><CopySourceFiles="@(LibFiles)"DestinationFolder="$(OutDir)\Deploy\Lib"/><CopySourceFiles="@(ToolsFiles)"DestinationFolder="$(OutDir)\Deploy\Tools"/></Target></Project>

Why does VS complain about that element? Any other options?

--
Werner