I have a question : i've upgrade dovecot from 1.1.4 to 2.0.9 and everything is fine except thunderbird clients , that no longer show a popup when new mail arrives. Anyone know why ?

doveconf -n: # 2.0.9: /usr/dovecot2/etc/dovecot/dovecot.conf # OS: Linux 2.6.35.4 i686 auth_cache_negative_ttl = 10 secs auth_cache_size = 10 M auth_cache_ttl = 1 mins auth_mechanisms = plain login cram-md5 auth_socket_path = /var/run/dovecot/auth-userdb auth_verbose_passwords = plain base_dir = /var/run/dovecot/ default_client_limit = 5000 default_internal_user = vmail default_login_user = nobody default_process_limit = 200 deliver_log_format = mail from=%f subject=%s msgid=%m: %$ dict { acl = mysql:/usr/dovecot2/etc/dovecot/dovecot-dict-sql.conf.ext } disable_plaintext_auth = no first_valid_uid = 1 lda_mailbox_autocreate = yes lda_mailbox_autosubscribe = yes listen = * mail_location = maildir:~/Maildir mail_plugins = " quota acl trash notify mail_log" managesieve_notify_capability = mailto managesieve_sieve_capability = fileinto reject envelope encoded-character vacation subaddress comparator-i;ascii-numeric relational regex imap4flags copy include variables body enotify environment mailbox date namespace { inbox = yes location = prefix = separator = / subscriptions = yes type = private } namespace { hidden = no list = children location = maildir:%%h/Maildir:INDEX=~/Maildir/shared/%%u prefix = shared/%%u/ separator = / subscriptions = no type = shared } passdb { args = /usr/dovecot2/etc/dovecot/dovecot-sql.conf.ext driver = sql } plugin { acl = vfile acl_shared_dict = proxy::acl autocreate = Trash autocreate2 = Drafts autocreate3 = Sent autosubscribe = Trash autosubscribe2 = Drafts autosubscribe3 = INBOX autosubscribe4 = Sent mail_log_events = delete mailbox_delete mailbox_rename mail_log_group_events = yes quota = maildir:User quota quota_warning = storage=95%% quota-warning 95 %u quota_warning2 = storage=95%% quota-warning 90 %u quota_warning3 = storage=85%% quota-warning 85 %u sieve = ~/.dovecot.sieve sieve_dir = ~/sieve trash = /usr/dovecot2/etc/dovecot/dovecot-trash.conf.ext } postmaster_address = postmaster@dacris.net protocols = imap rejection_subject = Rejected: %s: %r service auth { unix_listener auth-userdb { mode = 0660 user = vmail } } service dict { unix_listener dict { user = vmail } } service imap-login { process_min_avail = 16 service_count = 1 } service imap { process_limit = 2048 vsz_limit = 512 M } service quota-warning { executable = script /bin/quota_warning.sh unix_listener quota-warning { user = vmail } user = vmail } ssl_cert = </etc/ssl/certs/dovecot.pem ssl_key = </etc/ssl/private/dovecot.pem userdb { args = /usr/dovecot2/etc/dovecot/dovecot-sql.conf.ext driver = sql } protocol lda { mail_plugins = " quota acl trash notify mail_log sieve autocreate" } protocol imap { mail_plugins = " quota acl trash notify mail_log imap_quota imap_acl" }