Avast 5 Home addition Error message

Hi
Running Avast 5 Home addition on Windows 7 and am getting the error message.
avast. unable to open attached message. Error Code 0x80030003

Should have also added that the messages is when sending mail from outlook 2007

help needed. mail seems to get sent ok.

I have the same error. Config: Windows XP Pro SP3 / Office 2007. Any suggestions?