title: Clarification on .Net version(2.0, 3.5, 1.1) COM add-in behavior with .Net 4.0 Process
body: <p>Scenario:
  An application targeting .Net 3.5 is perfectly able to add COM add-ins targeting .Net framework 1.1, 2.0 or 3.5.</p>
  
  <p>As soon as the same application is migrated to target framework 4.0. Some of these add-ins started giving issues mainly with com calls, same calls works fine when application targets framework 3.5.</p>
  
  <p>Using config attribute... "useLegacyV2RuntimeActivationPolicy="true"", which Enable .NET Framework 2.0 runtime activation policy for the chosen runtime, which is to bind legacy runtime activation techniques (such as the CorBindToRuntimeEx function) to the runtime chosen from the configuration file instead of capping them at CLR version 2.0. Some of these add-in earlier giving problem started working fine with target .Net 4.0.</p>
  
  <p>Still some of them fail because of this attribute, and once removed those which worked because of this starts to fail.</p>
  
  <p>Any suggestion to make all of these add-ins work with target framework 4.0?</p>