Today I again had the issue, that Database Quotas have not been synced between IBM Domino Cluster servers. After some search, I found the following post:

http://tippner.blogspot.co.at/2011/08/synchronizing-database-quotas.html

I did some modifications in the code and ran the agent with the Server ID and scheduled the agent one time a day… So far it´s looking fine…

You can download the database here: https://www.dropbox.com/s/9ebh3r0qh4hl6ft/sync_dbquotas.nsf?dl=1