call to shell32 wrapper dll does not work in web service

[mugo4real]

I have used tlbimp.exe to create a wrapper dll for shell32.dll

My code referencing this wrapper dll works perfectly when
I use it in a console application.

The exact same code fails

(Shell.NameSpace()

returns null)
when I use it in a web service.

I am using C# and .net framework and SDK 2.0

Regards,

Eric.