Execution Permission Cannot Be Acquired

Hi

I have a CLR assembly loaded (UNSAFE) in SQL Server 2005. Assembly is in written C#. It calls functions from another assembly (also successfully created in SQL Server) written in Managed C++ and compiled with /clrure. The later one calls functions from native DLL. When I try to call one of the functions from my C# assembly I get this:

Msg 6522, Level 16, State 1, Line 1

A .NET Framework error occurred during execution of user-defined routine or aggregate "MyClrFunction":

System.TypeInitializationException: The type initializer for '<Module>' threw an exception. ---> System.IO.FileLoadException: Could not load file or assembly 'msvcm80, Version=8.0.50727.1433, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. Failed to grant permission to execute. (Exception from HRESULT: 0x80131418) ---> System.Security.Policy.PolicyException: Execution permission cannot be acquired.

System.Security.Policy.PolicyException:

at System.Security.SecurityManager.ResolvePolicy(Evidence evidence, PermissionSet reqdPset, PermissionSet optPset, PermissionSet denyPset, PermissionSet& denied, Boolean checkExecutionPermission)

at System.Security.SecurityManager.ResolvePolicy(Evidence evidence, PermissionSet reqdPset, PermissionSet optPset, PermissionSet denyPset, PermissionSet& denied, Int32& securitySpecialFlags, Boolean checkExecutionPermission)

System.IO.FileLoadException:

at <CrtImplementationDetails>.ThrowNestedModuleLoadException(Exception , Exception )

at <CrtImplementationDetails>.LanguageSupport.Cleanup(LanguageSupport* , Exception innerException)

at <CrtImplementationDetails>.LanguageSupport.Initialize(LanguageSupport* )

at .cctor()

System.TypeInitializationException:

at Functions.MyClrFunction(SqlString key)

.
Calls into C# assembly work perfectly. Calls into C++ assembly produce the above message no matter what I don inside (even if I just return immediately).
Any hints what's wrong? Or at least how I can track this down?