>Look in the ItemGroup/Reference elements of the project file (although I'm not sure whether VB is the same as C#)

For that particular application, at the application level, I have this:

  <ItemGroup>
    <Reference Include="FlexCel, Version=6.2.1.0, Culture=neutral, PublicKeyToken=cb8f6080e6d5a4d6, processorArchitecture=MSIL">
      <SpecificVersion>False</SpecificVersion>
      <HintPath>..\..\iis\ApplicationNameHere\bin\FlexCel.dll</HintPath>
    </Reference>
    <Reference Include="Framework, Version=1.0.2280.42083, Culture=neutral, processorArchitecture=MSIL">
      <SpecificVersion>False</SpecificVersion>
      <HintPath>..\Framework\bin\Framework.dll</HintPath>
    </Reference>
    <Reference Include="Generic, Version=1.0.5399.27039, Culture=neutral, processorArchitecture=MSIL">
      <SpecificVersion>False</SpecificVersion>
      <HintPath>..\Generic\bin\Generic.dll</HintPath>
    </Reference>
    <Reference Include="System" />
    <Reference Include="System.Data" />
    <Reference Include="System.Drawing" />
    <Reference Include="System.EnterpriseServices" />
    <Reference Include="System.Web.Services" />
    <Reference Include="System.Windows.Forms" />
    <Reference Include="System.Xml" />
  </ItemGroup>

FlexCel is a 3rd party. The other two are under my own management.

I do not see anything specific in there that would target 2.0.

As far as the Item\Reference for the Framework.dll, as this one is the same as when being run on the Web site, and the Web site does not fail, I did not include the reference in here as it seems to be application related.