Visual Studio 2010 Prof: Solution Explorer does not show files from Import.targets

Since I have many configurations for one project, I wanted to clean up .csproj a bit.
I moved all the config definitions to separate files using the Conditional ItemGroup and imported them into .csproj with:

<Import Project="conf/file.targets">

Everything seems fine, except for one, in explorer explorer I do not see the files that are defined in .targets, but the project compiles without any problems. Is this a mistake or normal behavior? How can I view files imported from .targets? (for example, SomeFile and SomeFile2.)
Example test.targets:

<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">

  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'TestConfig|x86'">
    <OutputPath>bin\TestConfig\</OutputPath>
    <DefineConstants>TRACE</DefineConstants>
    <Optimize>true</Optimize>
    <DebugType>pdbonly</DebugType>
    <PlatformTarget>x86</PlatformTarget>
    <GenerateSerializationAssemblies>Off</GenerateSerializationAssemblies>
    <ErrorReport>prompt</ErrorReport>
  </PropertyGroup>

  <ItemGroup Condition=" '$(Configuration)'=='TestConfig' ">
    <Compile Include="SomeFile.cs" />
    <Compile Include="SomeFile2.cs" />
  </ItemGroup>

</Project>

Everything was visible in Solution Explroer when it was defined in .csproj.

PS. I searched on google and stackoverflow, but did not find useful information.