diff --git a/xtandempipeline/src/fr/inra/pappso/xtandempipeline/class_msms/MsRun.java b/xtandempipeline/src/fr/inra/pappso/xtandempipeline/class_msms/MsRun.java
index 86dae80c524e26ad4cc6b35e040536c992d563e7..bf927ea3a675867696994b8b2473bd6a6045454e 100644
--- a/xtandempipeline/src/fr/inra/pappso/xtandempipeline/class_msms/MsRun.java
+++ b/xtandempipeline/src/fr/inra/pappso/xtandempipeline/class_msms/MsRun.java
@@ -6,11 +6,12 @@ import org.apache.log4j.Logger;
 
 import fr.inra.pappso.xtandempipeline.class_msms.IdentificationDataFile.IdentificationDataSource;
 
-public class MsRun implements Comparable<MsRun>{
+public class MsRun implements Comparable<MsRun> {
 	private static final Logger logger = Logger.getLogger(MsRun.class);
 	private String sample;
 
-	private HashSet<IdentificationDataSource> files = new HashSet<IdentificationDataSource>(0);
+	private HashSet<IdentificationDataSource> files = new HashSet<IdentificationDataSource>(
+			0);
 
 	public MsRun(String sample_name) {
 		logger.debug("MsRun begin");
@@ -18,10 +19,10 @@ public class MsRun implements Comparable<MsRun>{
 	}
 
 	public IdentificationDataSource addFile(IdentificationDataSource file) {
-		if(files.add(file)) {
+		if (files.add(file)) {
 			return file;
 		}
-		for (IdentificationDataSource otherFile:this.files) {
+		for (IdentificationDataSource otherFile : this.files) {
 			if (file.equals(otherFile)) {
 				return otherFile;
 			}
@@ -32,16 +33,25 @@ public class MsRun implements Comparable<MsRun>{
 	public String getSampleName() {
 		return sample;
 	}
-	
+
 	@Override
 	public int hashCode() {
 		return sample.hashCode();
 	}
-	
+
 	@Override
 	public boolean equals(Object toCompare) {
 		if (this.hashCode() == toCompare.hashCode()) {
-			return true;
+			MsRun msRunCompare = (MsRun) toCompare;
+			if (this.sample.equals(msRunCompare.sample)) {
+				return true;
+			}
+
+			else {
+				logger.debug("msRun COLLISION on " + sample + " compared to "
+						+ msRunCompare.sample);
+
+			}
 		}
 		return false;
 	}
@@ -49,5 +59,5 @@ public class MsRun implements Comparable<MsRun>{
 	public int compareTo(MsRun arg0) {
 		return this.sample.compareTo(arg0.sample);
 	}
-	
+
 }