--- /tmp/mysql-4.1.25/sql/table.cc	Tue Dec 30 06:13:27 2008
+++ /usr/src/mysql-4.1.25/sql/table.cc	Mon Jun 14 15:38:27 2010
@@ -633,10 +633,9 @@
 	      keyinfo->flags|= HA_END_SPACE_KEY;
 	  }
 	  if (i == 0 && key != primary_key)
-	    field->flags |=
-	      ((keyinfo->flags & HA_NOSAME) &&
-	       field->key_length() ==
-	       keyinfo->key_length ? UNIQUE_KEY_FLAG : MULTIPLE_KEY_FLAG);
+            field->flags |= ((keyinfo->flags & HA_NOSAME) &&
+	                      (keyinfo->key_parts == 1)) ?
+	                    UNIQUE_KEY_FLAG : MULTIPLE_KEY_FLAG;
 	  if (i == 0)
 	    field->key_start.set_bit(key);
 	  if (field->key_length() == key_part->length &&