Index: core/src/main/java/quickfix/FileLog.java
===================================================================
--- core/src/main/java/quickfix/FileLog.java	(revision 918)
+++ core/src/main/java/quickfix/FileLog.java	(working copy)
@@ -27,6 +27,8 @@
 import java.io.UnsupportedEncodingException;
 
 import org.quickfixj.CharsetSupport;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import quickfix.field.converter.UtcTimestampConverter;
 
@@ -37,6 +39,7 @@
  * @see quickfix.FileLogFactory
  */
 public class FileLog extends AbstractLog {
+    private Logger log = LoggerFactory.getLogger(getClass());
     private static final byte[] TIME_STAMP_DELIMETER;
     static {
         try {
@@ -143,7 +146,7 @@
             closeFiles();
             openLogStreams(false);
         } catch (IOException e) {
-            System.err.println("Could not clear log: "+getClass().getName());
+            log.error("Could not clear log: "+getClass().getName(), e);
         }
     }
 }
\ No newline at end of file
Index: core/src/main/java/quickfix/JdbcLog.java
===================================================================
--- core/src/main/java/quickfix/JdbcLog.java	(revision 918)
+++ core/src/main/java/quickfix/JdbcLog.java	(working copy)
@@ -31,7 +31,11 @@
 
 import javax.sql.DataSource;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 class JdbcLog extends AbstractLog {
+    private Logger log = LoggerFactory.getLogger(getClass());
     private static final String DEFAULT_MESSAGES_LOG_TABLE = "messages_log";
     private static final String DEFAULT_EVENT_LOG_TABLE = "event_log";
     private final String outgoingMessagesTableName;
@@ -146,8 +150,7 @@
         Connection connection = null;
         PreparedStatement insert = null;
         if (recursiveException != null) {
-            System.err.println("JdbcLog cannot log SQLException due to recursive log errors!");
-            recursiveException.printStackTrace();
+            log.error("JdbcLog cannot log SQLException due to recursive log errors!", recursiveException);
             recursiveException = null;
             return;
         }