Interop.Domino dll is Thread safe?

Hi,

  I need to know whether the Interop.Domino dll 1.2.0.0 version is thread safe or not ?



  As i am using in c# Application with multithreading, and for the large NSF files, the threads are getting failed.



  I also tried by releasing the com instances by using Marshal.RleaseComObject(object).



  Please reply, if any one has some idea.



  Thanks in advance.