Hi,
I keep having my sync breaking , i restart and often this fixes the issue.

I had this error at same time when i went to a diff server to ban a player...
http://pastebin.com/Lk5E6xYU

[13:12:11] [Craft Scheduler Thread - 3297/WARN]: Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry 'áÑy�ë�LŒÙë5�ë�ˆ' for key 'bm_player_bans_player_idx'

There were a few similar issue reports AFAIR. Check the closed ones for duplicate entry.

oh ok , has latest upsates fixed it ?

If you're running BM using a local setup to sync bans across multiple servers, why are you re-banning on each server manually?

If the amount of time it takes for the bans to sync across all servers is too long, edit your schedules.yml accordingly.