ot: win7 Tbird IMAP issues

I have a user with with W7/TBird/IMAP on centos/dovecot 2.x server, the
user complains whilst he is composing lengthy emails (with multiple
fowrds/replies quoted in the message) he gets 'hour glass' over compose
windows with some message about not being able to save to draft folder,

he then powers off ADSL modem, which enables him to continue composing
email, powers on ADSL, and sends email

any TB tips, what to enable or disable on TB ?

I think the user keeps many messages open concurrently in TB tabs, could
that exhaust connection limit ?

googling shows many similar symptoms that I'm slowly reviewing, but hoping
maybe someone came across similar issues

-- 
SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/
Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html