Silverlight2.0 Security Tighened??

I am trying to migrate my existing Silverlight 1.1 control to 2.0 version. I noticed another change. Access to other Dlls placed in the folder is denied by System.Reflection. In other words, the Assembly.Load(fullname) does not work unless a reference is added to the assembly.
Though one may say that it is a security feature, it was happening in 1.1. And I dont think loading a silverlight dll from the ClientBin directly will affect the security in anyways.