http://blogs.msdn.com/shawnfa/archive/2006/09/21/764977.aspxIf you construct an RSACryptoServiceProvider class without specifying a name for the key, the CLR will create a random ephemeral key for you. However, ephemeral keys are not supported by the underlying CAPI APIs on all of the platforms that the CLR wasen-USCommunityServer 2.1 SP1 (Build: 61025.2)http://blogs.msdn.com/shawnfa/archive/2006/09/21/764977.aspx#765554Fri, 22 Sep 2006 06:13:47 GMT91d46819-8472-40ad-a661-2c78acb4018c:765554Jason Haleyhttp://blogs.msdn.com/shawnfa/archive/2006/09/21/764977.aspx#766157Fri, 22 Sep 2006 16:39:21 GMT91d46819-8472-40ad-a661-2c78acb4018c:766157Guido DomeniciI was casually reading this blog entry via my normal RSS feed, while trying to debug a seemingly unsurmountable problem in my code. Then, suddenly I counted 1+1=2 and realized that this article I was reading by pure coincidence was exactly the solution to my problem! The finalizer thread turned out to be running as the non-impersonated user, thus not being able to delete the ephemeral key. Thanks guys, you saved my day.