StringMatchFilter isn't rejecting log events

[Baron Schwartz]

Hi,

We went over this recently on the list -- what am I doing wrong?  I'm
getting messages with the string "FK_ListingCostByDay_Listing" in them. 
Here's my config.  Thanks in advance for your help!

Baron

    <log4net>
        <appender name="SmtpAppender" type="log4net.Appender.SmtpAppender">
.... [some stuff omitted] ....
            <filter type="log4net.Filter.StringMatchFilter">
                <param name="AcceptOnMatch" value="false" />
                <param name="StringToMatch"
value="FK_ListingCostByDay_Listing" />
            </filter>
        </appender>
        <root>
            <level value="ERROR" />
            <appender-ref ref="SmtpAppender" />
        </root>