Dynamically changing Smart GWT log level

I am trying to change the Smart GWT log level dynmically but to no avail. If the user changes the Loggging level in my form, on the server side I am doing the following:

Logger smartGwtLogger = Logger.getLogger("com.isomorphic");
if (smartGwtLogger != null) {
Level currentLogLevel = smartGwtLogger.getLevel();
if (!currentLogLevel.equals(newLevel)) {
smartGwtLogger.setLevel(newLevel);
}
}

The code gets executed OK but Smart GWT continues to log at whatever level was set in the log4j.isc.config.xml.

Am I doing something wrong? The above approach works fine for our logging.