It looks like your mixing nant and msbuild, if it was msbuild it would look like
<Project xmlns="http://schemas.microsoft.com/developer/msbuild/2003" Tools="4.0">
<Target Name="Move">
<PropertyGroup>
<configuration>CLOSED</configuration>
</PropertyGroup>
<Move SourceFiles="Somefilefile" DestinationFolder="c:\temp"/>
</Target>
</Project>
So casing was an issue and that you need to specify the tools version as move is available from 4.0.