Avoid log trace of external framework J2EE

I have an J2EE application with Liferay using an external framework (DWR). That framework is tracing in the log a lot of useless info with "INFO" level.

I have set the package of framework (uk.ltd.getahead.dwr) with "ERROR" level, however this is not working.

Liferay uses log4j. I have searched about it and DWR uses log4j too.