I had some friends run into a lot of challenges trying to write a utility that converted/persisted PDF files into a SQL 2005 Database using assemblies hosted inside of SQLCLR.  Turns out they were running into a limitation in SQL I didn't know about -That SQL only suports a subset of the .NET Framework classes those NOT marked as Host Protection Attributes -regardless of marking the assembly as being "Unsafe".  After finding Tims Blog post -it still took a little while to find this in the documentation -sigh...

 http://blogs.msdn.com/tims/archive/2004/05/27/142798.aspx

http://msdn2.microsoft.com/en-us/library/ms403276.aspx

 

HostProtection

 System.Windows.Forms

System.Drawing