diff --git a/src/java/com/threerings/io/ObjectInputStream.java b/src/java/com/threerings/io/ObjectInputStream.java
index 6cb8d39e4..4f7a7675d 100644
--- a/src/java/com/threerings/io/ObjectInputStream.java
+++ b/src/java/com/threerings/io/ObjectInputStream.java
@@ -1,5 +1,5 @@
 //
-// $Id: ObjectInputStream.java,v 1.1 2002/07/23 05:42:34 mdb Exp $
+// $Id: ObjectInputStream.java,v 1.2 2002/12/02 22:10:10 mdb Exp $
 
 package com.threerings.io;
 
@@ -8,6 +8,7 @@ import java.io.DataInputStream;
 import java.io.IOException;
 
 import com.samskivert.util.HashIntMap;
+import com.samskivert.util.StringUtil;
 
 import com.threerings.presents.Log;
 
@@ -79,7 +80,14 @@ public class ObjectInputStream extends DataInputStream
 
                 // sanity check
                 if (cmap == null) {
-                    String errmsg = "Aiya! Read object code for which we " +
+                    // this will help with debugging
+                    Log.warning("Internal stream error, no class metadata " +
+                                "[code=" + code + ", ois=" + this + "].");
+                    Thread.dumpStack();
+                    Log.warning("ObjectInputStream mappings " +
+                                StringUtil.toString(_classmap.entrySet()) +
+                                ".");
+                    String errmsg = "Read object code for which we " +
                         "have no registered class metadata [code=" + code + "]";
                     throw new RuntimeException(errmsg);
                 }
@@ -147,6 +155,16 @@ public class ObjectInputStream extends DataInputStream
         _streamer.readObject(_current, this, false);
     }
 
+    /**
+     * Generates a string representation of this instance.
+     */
+    public String toString ()
+    {
+        return "[hash=" + hashCode() + ", mappings=" + _classmap.size() +
+            ", current=" + StringUtil.safeToString(_current) +
+            ", streamer=" + _streamer + "]";
+    }
+
     /**
      * Used by a {@link Streamer} that is reading an array of {@link
      * Streamable} instances.
diff --git a/src/java/com/threerings/io/Streamer.java b/src/java/com/threerings/io/Streamer.java
index 8cbc786a4..eadb4c2ad 100644
--- a/src/java/com/threerings/io/Streamer.java
+++ b/src/java/com/threerings/io/Streamer.java
@@ -1,5 +1,5 @@
 //
-// $Id: Streamer.java,v 1.1 2002/07/23 05:42:34 mdb Exp $
+// $Id: Streamer.java,v 1.2 2002/12/02 22:10:10 mdb Exp $
 
 package com.threerings.io;
 
@@ -299,6 +299,16 @@ public class Streamer
         }
     }
 
+    /**
+     * Generates a string representation of this instance.
+     */
+    public String toString ()
+    {
+        return "[target=" + _target.getName() + ", delegate=" + _delegate +
+            ", fcount=" + _fields.length + ", reader=" + _reader +
+            ", writer=" + _writer + "]";
+    }
+
     /**
      * The constructor used by the basic streamers.
      */