Reference to Microsoft.SQLServer.ManagedDTS.dll only works if Target Framework set to .Net 4.0

Hi all ,

I have a console application previously created in  .net version 2.0 and   has a refrence to Microsoft.SQLServer.ManagedDTS.

This refrence is from folder /ProgramFile (X86)/90/Assembles (do not remember exact path.)

My machine has SQL 2005 and SQL 2008 installed along with SSIS component . VS 2010 ultimate edition is installed for Dot net .

Following things happen when I open console application in 2010  keeping version as 2.0.

1) When classes in console application laoded for first time , class has proper refrence to Dts.Runtime.Package namespace and it is referring Microsoft.SQLServer.ManagedDTS dll in 90 folder.

2) But once solution is compiled , appliaction gives an error saying "Dts.Runtime.Package" does not exist .

3) If I change solution version to 4.0 , it compiles properely .

I am trying to resolve this issue . Strange thing is DLL is properely in place .

Any help will be really appreciated .

Thanks

Siddhesh

Siddhesh Sawant