SDK - Object API

I'm trying to add a signature to a message, having challenges working with the GroupwareTypeLibrary / namespace in visual studio...

The SDK Guide is pretty 'light' regarding signature functionality...

I am able to generate/send an email without any problems...

In debug mode, I can see the default signature, re:

oSignature = oAccount.Signatures.GetDefault()

oSignature.Name reflects the default signature associated with the login...

I set the SignatureDisplayFlag=3 in the Account7 structure (re: always include signature according to the documentation) and tested,
the email generated and delivered without any errors, but without the signature block at the end of the message body...

I'm not sure where to go from here, what I am missing ?

Any insight / thoughts appreciated, thks in advance !!

G