diff --git a/genomix/genomix-hadoop/src/main/java/edu/uci/ics/genomix/hadoop/graphclean/mergepaths/h4/MergePathsH4.java b/genomix/genomix-hadoop/src/main/java/edu/uci/ics/genomix/hadoop/graphclean/mergepaths/h4/MergePathsH4.java
index afdb46e..2f12606 100644
--- a/genomix/genomix-hadoop/src/main/java/edu/uci/ics/genomix/hadoop/graphclean/mergepaths/h4/MergePathsH4.java
+++ b/genomix/genomix-hadoop/src/main/java/edu/uci/ics/genomix/hadoop/graphclean/mergepaths/h4/MergePathsH4.java
@@ -342,9 +342,11 @@
                                     + outputValue.getNode() + "  current self: " + inputValue.getNode());
                         if (inMsg == MessageFlag.MSG_SELF) {
                             outPosn.set(outputValue.getNode().getNodeID());
-                        } else { // MSG_UPDATE_MERGE
+                        } else if (inMsg == MessageFlag.MSG_UPDATE_MERGE) {
                             // merge messages are sent to their merge recipient
                             outPosn.set(outputValue.getNode().getListFromDir(inMsg).getPosition(0));
+                        } else {
+                            throw new IOException("Unrecongized MessageFlag MSG: " + inMsg);
                         }
                         outputValue.set(inFlag, inputValue.getNode());
                         sawCurNode = true;
@@ -392,6 +394,7 @@
         private int mergeMsgsCount;
 
         public void configure(JobConf conf) {
+            mos = new MultipleOutputs(conf);
             KMER_SIZE = conf.getInt("sizeKmer", 0);
             inputValue = new NodeWithFlagWritable(KMER_SIZE);
             outputValue = new NodeWithFlagWritable(KMER_SIZE);
@@ -500,6 +503,9 @@
 
         // step 2: process merges
         FileInputFormat.addInputPaths(conf, outputUpdatesTmp);
+        for (Path out : FileInputFormat.getInputPaths(conf)) {
+            System.out.println(out);
+        }
         Path outputMergeTmp = new Path("h4.mergeProcessed." + new Random().nextDouble() + ".tmp"); // random filename
         FileOutputFormat.setOutputPath(conf, outputMergeTmp);
         MultipleOutputs.addNamedOutput(conf, H4MergeReducer.TO_UPDATE_OUTPUT, MergePathMultiSeqOutputFormat.class,
diff --git a/genomix/genomix-hadoop/src/test/java/edu/uci/ics/genomix/hadoop/graphclean/mergepaths/h3/TestPathMergeH3.java b/genomix/genomix-hadoop/src/test/java/edu/uci/ics/genomix/hadoop/graphclean/mergepaths/h3/TestPathMergeH3.java
index 058271e..7a65d59 100644
--- a/genomix/genomix-hadoop/src/test/java/edu/uci/ics/genomix/hadoop/graphclean/mergepaths/h3/TestPathMergeH3.java
+++ b/genomix/genomix-hadoop/src/test/java/edu/uci/ics/genomix/hadoop/graphclean/mergepaths/h3/TestPathMergeH3.java
@@ -16,7 +16,7 @@
 
 @SuppressWarnings("deprecation")
 public class TestPathMergeH3 extends GenomixMiniClusterTest {
-    protected String LOCAL_SEQUENCE_FILE = "src/test/resources/data/sequence/fr_test2.txt";
+    protected String LOCAL_SEQUENCE_FILE = "src/test/resources/data/sequence/bubble_test1.txt";
     protected String HDFS_SEQUENCE = "/00-sequence/";
     protected String HDFS_GRAPHBUILD = "/01-graphbuild/";
     protected String HDFS_MARKPATHS = "/02-pathmark/";
@@ -71,7 +71,7 @@
         FileOutputFormat.setOutputPath(buildConf, new Path(HDFS_GRAPHBUILD));
         buildConf.set(GenomixJobConf.OUTPUT_FORMAT, GenomixJobConf.OUTPUT_FORMAT_BINARY);
         buildConf.set(GenomixJobConf.GROUPBY_TYPE, GenomixJobConf.GROUPBY_TYPE_PRECLUSTER);
-        driver.runJob(new GenomixJobConf(buildConf), Plan.BUILD_UNMERGED_GRAPH, true);
+        driver.runJob(new GenomixJobConf(buildConf), Plan.BUILD_DEBRUJIN_GRAPH, true);
         String fileFormat = buildConf.get(GenomixJobConf.OUTPUT_FORMAT);
         boolean resultsAreText = GenomixJobConf.OUTPUT_FORMAT_TEXT.equalsIgnoreCase(fileFormat);
         copyResultsToLocal(HDFS_GRAPHBUILD, ACTUAL_ROOT + GRAPHBUILD_FILE, resultsAreText, buildConf);
diff --git a/genomix/genomix-hadoop/src/test/java/edu/uci/ics/genomix/hadoop/graphclean/mergepaths/h4/TestPathMergeH4.java b/genomix/genomix-hadoop/src/test/java/edu/uci/ics/genomix/hadoop/graphclean/mergepaths/h4/TestPathMergeH4.java
index 126e7a5..249af29 100644
--- a/genomix/genomix-hadoop/src/test/java/edu/uci/ics/genomix/hadoop/graphclean/mergepaths/h4/TestPathMergeH4.java
+++ b/genomix/genomix-hadoop/src/test/java/edu/uci/ics/genomix/hadoop/graphclean/mergepaths/h4/TestPathMergeH4.java
@@ -37,8 +37,8 @@
     @Test
     public void testTwoReads() throws Exception {
         setupTestConf(5, 8, false, "tworeads.txt");
-        testPathNode();
-//        testMergeOneIteration();
+//        testPathNode();
+        testMergeOneIteration();
 //        testMergeToCompletion();
     }
     
@@ -90,9 +90,9 @@
         if (regenerateGraph) {
             copyLocalToDFS(LOCAL_SEQUENCE_FILE, SEQUENCE);
             buildGraph();
-            copyLocalToDFS(ACTUAL_ROOT + GRAPHBUILD + ".bindir", GRAPHBUILD);
+            copyLocalToDFS(ACTUAL_ROOT + GRAPHBUILD + readsFile + ".binmerge", GRAPHBUILD);
         } else {
-            copyLocalToDFS(EXPECTED_ROOT + GRAPHBUILD + ".bindir", GRAPHBUILD);
+            copyLocalToDFS(EXPECTED_ROOT + GRAPHBUILD + readsFile + ".binmerge", GRAPHBUILD);
         }
     }
 }