Gmail folders always deleted/re-downloaded NOT synced?

[Tom Marble]

All:

I am trying to prepare to move to notmuch and have started by configuring
offlineimap for my Gmail account

As I have many folders and tons of e-mail I want to verify that the synchronization
is working with one minor folder (before trying to download everything).

Every time I run offlineimap on this one (rarely changing) folder it insists on deleting
all the mails and redownloading them:

tmarble at ficelle 114 :) offlineimap
OfflineIMAP 6.5.5
  Licensed under the GNU GPL v2+ (v2 or any later version)
Account sync tmarble at info9.net:
 *** Processing account tmarble at info9.net
 Establishing connection to imap.gmail.com:993
Folder Gmail/Associations/Breck [acc: tmarble at info9.net]:
 Syncing Gmail/Associations/Breck: Gmail -> Maildir
 Deleting 140 messages (1:140) in Maildir[Gmail.Associations.Breck]
Folder [Gmail]/Associations/Breck [acc: tmarble at info9.net]:
 Syncing [Gmail]/Associations/Breck: Gmail -> Maildir
 Copy message 1 (1 of 140) remote-info9.net:[Gmail]/Associations/Breck -> local-info9.net
 Copy message 2 (2 of 140) remote-info9.net:[Gmail]/Associations/Breck -> local-info9.net
...
 Copy message 139 (139 of 140) remote-info9.net:[Gmail]/Associations/Breck -> local-info9.net
 Copy message 140 (140 of 140) remote-info9.net:[Gmail]/Associations/Breck -> local-info9.net
Account sync tmarble at info9.net:
 *** Finished account 'tmarble at info9.net' in 0:50
tmarble at ficelle 115 :)

The remote config section has:
realdelete = no
maxage = 90
readonly = true
quick = -1

How can I ensure it just syncs?

--Tom


p.s. I am running on Debian unstable:

tmarble at ficelle 101 :) dpkg -l | grep offline
ii  offlineimap           6.5.5-0.1       all             IMAP/Maildir synchronization and reader support