[Dovecot] Dovecot imap with Postfix and using Thunderbird as client

[Ben Ware]

Hi,
I just recently installed dovecot, and I am having the following problem:
If I send an email to my account on this new machine, I can log in via 
SSH and use the unix mail command, and instantly my email is visible.  
If I turn on Thunderbird, it will show my new message.  If Thunderbird 
was already on and had already checked the mailbox, even if I click on 
get new mail for that specific mailbox, the new mail does not show up 
until I restart thunderbird.  Is there something that I have set wrong 
in the config files that is preventing the IMAP part of dovecot from 
refreshing the messages quickly for me to see?  I dont see anything in 
the log files at all except for it showing me logging in.
Thanks,
Ben