Table sync sql error duplicate entries

[gwugodevco]

I keep getting this problem for tables with UNIQUE KEY:

SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '1firstclassbarbershop@gmail.com-1' for key 'CUSTOMER_ENTITY_EMAIL_WEBSITE_ID'

this table has "entity_id" as the primary key and "email + website_id" as UNIQUE KEY.

I checked nothing changed for that particular record, so each time it hit the problem, i have to open the sql console, delete the row and re-run the db-sync script.

Please help. Thanks

-Gunardi Wu