As luck would have it, I can no longer reproduce this problem.  If you are seeing the triplication problem, could you please forward the following information about your system:
-Greg

J. Greg Mackinnon wrote:
[log in to unmask]" type="cite"> Oh yuck... sure enough... triplicate messages with 437.

I will revert the software download page to the 424 build, and see if there are any fixes available from ESET.

A workaround would be to disable email integration with Thunderbird:
  1. Open the NOD32 Antivirus Console, and enable "Advanced Mode":
    [log in to unmask]" alt="">
  2. Click "Setup" then "entire advanced setup tree":
    [log in to unmask]" alt="">
  3. Under "Miscellaneous", click "Email client integration", then deselect "Integrate into Mozilla Thunderbird":
    [log in to unmask]" alt="">

-Greg

Beth Wilkins wrote:
[log in to unmask]" type="cite">
Well I updated a user this morning to 437 and she is now complaining of
email in triplicate 

-----Original Message-----
From: Technology Discussion at UVM [mailto:[log in to unmask]] On
Behalf Of J. Greg Mackinnon
Sent: Thursday, July 02, 2009 12:15 PM
To: [log in to unmask]
Subject: Re: Triplicating email in Thunderbird?

I am running 4.0.424 without errors.  I will update to 437 and see what 
happens.  In theory, 437 should be better because 424 has a bug that can 
cause corruption of attachments in Thunderbird.  Perhaps the cure is 
worse than the disease?  We shall see...

-Greg

Bryan R. Fleming wrote:
  
So back in June I remember this problem running through the list, and 
I just double checked the archives.

I just upgraded a client to the latest version of eset Nod 32, had 
been on 3 now on 4.0.437.  Now their thunderbird imap email is being 
triplicated.  Happens in both accounts they have.  I've disabled the 
email integration of ESET for now. (as Andrew had reported they're 
'real' messages that show up in webmail)

Current virus signature is 4209 20090702l.

Anyone else encountering it today or is there something unique about 
the setup here?

-Bryan