Whitelist doesn't always work.

I recently purchased ESET Smart Security (currently ver. 4.0.437.0) and it does a nice job. Mostly.
The problem I am having is that some of the email addresses I have in the "Whitelist" still get dumped into the "Junk" folder. I am using Thunderbird (ver. 2.0.0.22). It does not mark it as "Spam", it just gets placed in the "Junk" folder. There are about 5 email addresses that this happens to out of about 40, and no matter how I try or how many times I try to whitelist them, it enters the address in the whitelist and then continues call them junk.
My understanding of a whitelist is that it is a pass no matter what.
What am I missing here?
Thanks for your help.
Richard

 

Since you said these emails are not marked as spam, I assume that it's the Thunderbird spam filter that moves them to that folder. You can verify it by disabling the antispam module for a while.