JCLLoggerAdapter contains:
public void trace(String format, Object arg1, Object arg2) {
if (log.isDebugEnabled())

{ FormattingTuple ft = MessageFormatter.format(format, arg1, arg2); log.trace(ft.getMessage(), ft.getThrowable()); }

}

log.isDebugEnabled() is used instead of log.isTraceEnabled()

Issue is present in the slf4j-jcl-1.7.2 for all trace methods.