SBS 2003 Standard : Exchange/SMTP File and Subject Blocking Config not saved

Hi

I have Avast 4.7 Server edition for SBS and 10 Clients running Office 2003.
When I used the Server Wizard to configure blocked files for attachments and subject text blocking the settings I enter are ignored and not saved. Next time I open the advanced config tool and look at the settings they have reverted back to blank.

This is casuing me a major headache with a customer so a quick response will be apprciated.

Neil