problem creating assembly using other assemblies

Hi,

I have developed a Stored procedure to output text to a text file, after doing a lot of reading here.
I want to be able to output data to a Postgres database, to be used for web mapping. I have referenced an Assembly Npgsql.dll so I can send updates to the postgres database when my ms sql database is updated. However, after building my class library, when I try to CREATE ASSEMBLY in sql server 2005 express, it sends out a message:
Msg 10301, Level 16, State 1, Line 1
Assembly 'ClassLibrary1' references assembly 'system.drawing, version=2.0.0.0, culture=neutral, publickeytoken=b03f5f7f11d50a3a.', which is not present in the current database. SQL Server attempted to locate and automatically load the referenced assembly from the same location where referring assembly came from, but that operation has failed (reason: 2(error not found)). Please load the referenced assembly into the current database and retry your request.
The error seems to be in the Npgsql.dll assembly, can anybody please shed some light on this.
I tried to load the system.drawing assembly, and can do so in Unrestricted mode. It then spits out the same problem for System.Windows.Forms.dll.
I am still very new to all of this so any help would be appreciated.
Cheers,
Jatz91.

I got around this problem.

I used CREATE ASSEMBLY with PERMISSION_SET=UNSAFE and put the Microsoft.NET Framework Assemblies in the same folder where my built assembly was.

When I used CREATE ASSEMBLY, a warning was spat out for each assembly saying:

Warning: The Microsoft .Net frameworks assembly 'system.drawing, version=2.0.0.0, culture=neutral, publickeytoken=b03f5f7f11d50a3a, processorarchitecture=msil.' you are registering is not fully tested in SQL Server hosted environment.

So now I run my CLR in UNSAFE mode

Cheers