[Dovecot] mail_index_sync_map error on 1.1.14

[Mike Abbott]

>> Panic: IMAP(user): file mail-index-sync-update.c: line 843  
>> (mail_index_sync_map): assertion failed: (map->hdr.indexid == index- 
>> >indexid || map->hdr.indexid == 0)
>
> Can you get the values of map->hdr.indexid and index->indexid?

Core dumps are now enabled so if it happens again I'll try to retrieve  
these values.

> looks like dovecot.index file was recreated by another Dovecot that
> didn't know about the existing index files (which shouldn't really be
> happening normally)

Even clustered over NFS?  Is this assertion a symptom of not tuning  
for a shared mailstore properly ala http://wiki.dovecot.org/MailLocation/SharedDisk 
  ?