Is your MySQL install GreenSQL firewalled?
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What is GreenSQL?
GreenSQL is an Open Source database firewall used to protect databases from SQL injection attacks. GreenSQL works as a proxy for SQL commands and has built in support for MySQL. The logic is based on evaluation of SQL commands using a risk scoring matrix as well as blocking known db administrative commands (DROP, CREATE, etc). GreenSQL is distributed under the GPL license. You can download it here.
More info at: http://www.greensql.net/about