XSD - problem with schema generation

Question

Hello I'm tring to generate schema for some type from assembly with xsd.exe here is command line : xsd.exe TestAssemby.dll /t:TestType

Here is error I got Error: There was an error processing 'TestAssemby.dll'. - Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information

I copied referenced dll into folder where is located according to http://social.msdn.microsoft.com/Forums/en/xmlandnetfx/thread/308e4f3a-e1c3-43f5-b7a6-a82f1395997d

but still get the same error

I have questions : 1) What can be possible reasons of such error ? 2) How should be used LoaderExceptions property ? ( example will be very helpful)

Thanks in advance