Thunderbird & Nod32 v.3x Prob

Odd. Thunderbird version 1.5.0.13 (2006030 won't deliver emails with attachments around 800kb and over. I get 'SMTP Server failed..server may be unavailable or is refusing SMTP connections..verify server setting is correct.' It is. Emails with smaller attachments go through without a hitch. If I remove Nod32 the bigger ones suddenly do, too. I thought Zone Alarm Pro/Security Suite might be an issue (I've used both, lately, not at the same time but with this version of Nod32.) However I turned that off, defaulting to Win Firewall. I even turned that off, as well - just to see.
The problem appears to be Nod32.
Any clues? Settings? Bugs?
All comments appreciated.
Cheers

 

What version of NOD32 are you using?

 

I'd try uninstalling ZA completely. You never know if only disabling a program suffices.

 

Nod32 Home Edition v.3.0.563 and Eset Smart Security v.3.0.563 (previously
V3.0.560.0 versions of Nod32 Antivirus (not home) and Smart Security.) All
trials.
The problem is with Nod. I've since found that the message is false. Various
attempts to send emails which give this message have all arrived at their
destination, though I assumed they hadn't. Some people have got six versions
(my 're-trys!)
Gone back to the last of the v2 series until the bugs are fixed. Incidentally,
absolutely no issues with v 2.70.39 (latest ZAPro/Security Suite included.)
There never was with Nod32 v.2xx .

 

Why, out of curiosity are you still using thunderbird 1.5 and not 2.0.0.6?