diff --git a/main/src/com/google/refine/InterProjectModel.java b/main/src/com/google/refine/InterProjectModel.java
index 529ee19c9..295042612 100644
--- a/main/src/com/google/refine/InterProjectModel.java
+++ b/main/src/com/google/refine/InterProjectModel.java
@@ -88,6 +88,15 @@ public class InterProjectModel {
     
     protected Map<String, ProjectJoin> _joins = new HashMap<String, ProjectJoin>();
     
+    /**
+     * Compute the ProjectJoin based on combination key, return the cached one from the HashMap if already computed
+     * 
+     * @param fromProject
+     * @param fromColumn
+     * @param toProject
+     * @param toColumn
+     * @return
+     */
     public ProjectJoin getJoin(String fromProject, String fromColumn, String toProject, String toColumn) {
         String key = fromProject + ";" + fromColumn + ";" + toProject + ";" + toColumn;
         if (!_joins.containsKey(key)) {
diff --git a/main/src/com/google/refine/expr/functions/Cross.java b/main/src/com/google/refine/expr/functions/Cross.java
index 0dfb6b783..e04ed5e0a 100644
--- a/main/src/com/google/refine/expr/functions/Cross.java
+++ b/main/src/com/google/refine/expr/functions/Cross.java
@@ -47,39 +47,39 @@ import com.google.refine.grel.Function;
 import com.google.refine.model.Project;
 
 public class Cross implements Function {
-
+    
     @Override
     public Object call(Properties bindings, Object[] args) {
         if (args.length == 3) {
             // from project is implied
             
-            Object wrappedCell = args[0]; // from cell
+            Object v = args[0]; // from cell
             Object toProjectName = args[1];
             Object toColumnName = args[2];
             
-            if (wrappedCell != null && wrappedCell instanceof WrappedCell &&
+            if (v != null && v instanceof String &&
                 toProjectName != null && toProjectName instanceof String &&
                 toColumnName != null && toColumnName instanceof String) {
                 
                 ProjectJoin join = ProjectManager.singleton.getInterProjectModel().getJoin(
                         ProjectManager.singleton.getProjectMetadata(((Project) bindings.get("project")).id).getName(),
-                        ((WrappedCell) wrappedCell).columnName, 
+                        (String) bindings.get("columnName"), 
                         (String) toProjectName, 
                         (String) toColumnName
                         );
                 
-                return join.getRows(((WrappedCell) wrappedCell).cell.value);
+                return join.getRows((String)v);
             }
         }
-        return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " expects a cell, a project name to join with, and a column name in that project");
+        return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " expects a string, a project name to join with, and a column name in that project");
     }
-
+    
     @Override
     public void write(JSONWriter writer, Properties options)
         throws JSONException {
     
         writer.object();
-        writer.key("description"); writer.value("TODO");
+        writer.key("description"); writer.value("join with anothe project by column");
         writer.key("params"); writer.value("cell c, string projectName, string columnName");
         writer.key("returns"); writer.value("array");
         writer.endObject();
diff --git a/main/src/com/google/refine/model/changes/MassReconChange.java b/main/src/com/google/refine/model/changes/MassReconChange.java
index 8556a4705..5e8eb2a13 100644
--- a/main/src/com/google/refine/model/changes/MassReconChange.java
+++ b/main/src/com/google/refine/model/changes/MassReconChange.java
@@ -37,12 +37,14 @@ import java.io.IOException;
 import java.io.LineNumberReader;
 import java.io.Writer;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Map;
 import java.util.Properties;
 
 import org.json.JSONException;
 import org.json.JSONWriter;
 
+import com.google.refine.ProjectManager;
 import com.google.refine.history.Change;
 import com.google.refine.model.Cell;
 import com.google.refine.model.Project;
@@ -71,6 +73,7 @@ public class MassReconChange implements Change {
     
     protected void switchRecons(Project project, Map<Long, Recon> reconMap) {
         synchronized (project) {
+            HashSet<String> flushedColumn = new HashSet<String>(); 
             for (Row row : project.rows) {
                 for (int c = 0; c < row.cells.size(); c++) {
                     Cell cell = row.cells.get(c);
@@ -78,6 +81,14 @@ public class MassReconChange implements Change {
                         Recon recon = cell.recon;
                         
                         if (reconMap.containsKey(recon.id)) {
+                            // skip the flushing if already done
+                            String columnName = project.columnModel.getColumnByCellIndex(c).getName();
+                            if (!flushedColumn.contains(columnName)) {
+                                ProjectManager.singleton.getInterProjectModel().flushJoinsInvolvingProjectColumn(project.id, 
+                                    columnName);
+                                flushedColumn.add(columnName);
+                            }
+                            
                             row.setCell(c, new Cell(cell.value, reconMap.get(recon.id)));
                         }
                     }
diff --git a/main/src/com/google/refine/model/changes/MassRowColumnChange.java b/main/src/com/google/refine/model/changes/MassRowColumnChange.java
index 979f7a548..871df7587 100644
--- a/main/src/com/google/refine/model/changes/MassRowColumnChange.java
+++ b/main/src/com/google/refine/model/changes/MassRowColumnChange.java
@@ -41,6 +41,7 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.Properties;
 
+import com.google.refine.ProjectManager;
 import com.google.refine.history.Change;
 import com.google.refine.model.Column;
 import com.google.refine.model.ColumnGroup;
@@ -80,6 +81,8 @@ public class MassRowColumnChange implements Change {
             project.rows.clear();
             project.rows.addAll(_newRows);
             
+            ProjectManager.singleton.getInterProjectModel().flushJoinsInvolvingProject(project.id);
+            
             project.update();
         }
     }
@@ -96,6 +99,8 @@ public class MassRowColumnChange implements Change {
             project.rows.clear();
             project.rows.addAll(_oldRows);
             
+            ProjectManager.singleton.getInterProjectModel().flushJoinsInvolvingProject(project.id);
+            
             project.update();
         }
     }