diff --git a/main/src/com/google/refine/ProjectManager.java b/main/src/com/google/refine/ProjectManager.java
index c6a744e8f..0be3d87ae 100644
--- a/main/src/com/google/refine/ProjectManager.java
+++ b/main/src/com/google/refine/ProjectManager.java
@@ -119,7 +119,6 @@ public abstract class ProjectManager {
             _projectsMetadata.put(project.id, projectMetadata);
         }
     }
- //----------Load from data store to memory----------------
 
     /**
      * Load project metadata from data storage
@@ -135,7 +134,6 @@ public abstract class ProjectManager {
      */
     protected abstract Project loadProject(long id);
 
-    //------------Import and Export from Refine archive-----------------
     /**
      * Import project from a Refine archive
      * @param projectID
@@ -154,7 +152,6 @@ public abstract class ProjectManager {
     public abstract void exportProject(long projectId, TarOutputStream tos) throws IOException;
 
 
- //------------Save to record store------------
     /**
      * Saves a project and its metadata to the data store
      * @param id
@@ -194,8 +191,9 @@ public abstract class ProjectManager {
     /**
      * Save project to the data store
      * @param project
+     * @throws IOException 
      */
-    protected abstract void saveProject(Project project);
+    protected abstract void saveProject(Project project) throws IOException;
 
     /**
      * Save workspace and all projects to data store
@@ -204,6 +202,7 @@ public abstract class ProjectManager {
     public void save(boolean allModified) {
         if (allModified || _busy == 0) {
             saveProjects(allModified);
+            // TODO: Only save workspace if it's dirty
             saveWorkspace();
         }
     }
@@ -227,7 +226,7 @@ public abstract class ProjectManager {
         }
     }
 
-    static protected final int s_projectFlushDelay = 1000 * 60 * 60; // 1 hour
+    static protected final int s_projectFlushDelay = 1000 * 60 * 15; // 15 minutes
     static protected final int s_quickSaveTimeout = 1000 * 30; // 30 secs
 
     /**
@@ -296,12 +295,29 @@ public abstract class ProjectManager {
                     saveProject(records.get(i).project);
                 } catch (Exception e) {
                     e.printStackTrace();
+                    // In case we're running low on memory, free as much as we can
+                    disposeUnmodifiedProjects();
+                }
+            }
+        }
+    }
+
+    /**
+     * Flush all unmodified projects from memory.
+     */
+    protected void disposeUnmodifiedProjects() {
+        synchronized (this) {
+            for (long id : _projectsMetadata.keySet()) {
+                ProjectMetadata metadata = getProjectMetadata(id);
+                Project project = _projects.get(id);
+                if (project != null && !project.getProcessManager().hasPending() 
+                        && metadata.getModified().getTime() < project.getLastSave().getTime()) {
+                        _projects.remove(id).dispose();
                 }
             }
         }
     }
 
-    //--------------Get from memory--------------
     /**
      * Gets the InterProjectModel from memory
      */
@@ -405,7 +421,6 @@ public abstract class ProjectManager {
      */
     public abstract HistoryEntryManager getHistoryEntryManager();
 
-    //-------------remove project-----------
 
     /**
      * Remove the project from the data store
@@ -434,7 +449,6 @@ public abstract class ProjectManager {
         }
     }
 
-    //--------------Miscellaneous-----------
 
     /**
      * Sets the flag for long running operations.  This will prevent
diff --git a/main/src/com/google/refine/io/FileProjectManager.java b/main/src/com/google/refine/io/FileProjectManager.java
index 472c1df2d..1fa219215 100644
--- a/main/src/com/google/refine/io/FileProjectManager.java
+++ b/main/src/com/google/refine/io/FileProjectManager.java
@@ -217,7 +217,7 @@ public class FileProjectManager extends ProjectManager {
     }
 
     @Override
-    protected void saveProject(Project project){
+    protected void saveProject(Project project) throws IOException{
         ProjectUtilities.save(project);
     }
 
diff --git a/main/src/com/google/refine/io/ProjectUtilities.java b/main/src/com/google/refine/io/ProjectUtilities.java
index 0599d5f26..4088cfeb9 100644
--- a/main/src/com/google/refine/io/ProjectUtilities.java
+++ b/main/src/com/google/refine/io/ProjectUtilities.java
@@ -35,6 +35,7 @@ package com.google.refine.io;
 
 import java.io.File;
 import java.io.FileOutputStream;
+import java.io.IOException;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipFile;
 import java.util.zip.ZipOutputStream;
@@ -50,7 +51,7 @@ import com.google.refine.util.Pool;
 public class ProjectUtilities {
     final static Logger logger = LoggerFactory.getLogger("project_utilities");
 
-    synchronized public static void save(Project project) {
+    synchronized public static void save(Project project) throws IOException {
         synchronized (project) {
             long id = project.id;
             File dir = ((FileProjectManager)ProjectManager.singleton).getProjectDir(id);
@@ -58,11 +59,15 @@ public class ProjectUtilities {
             File tempFile = new File(dir, "data.temp.zip");
             try {
                 saveToFile(project, tempFile);
-            } catch (Exception e) {
+            } catch (IOException e) {
                 e.printStackTrace();
-
                 logger.warn("Failed to save project {}", id);
-                return;
+                try {
+                    tempFile.delete();
+                } catch (Exception e2) {
+                    // just ignore - file probably was never created.
+                }
+                throw e;
             }
 
             File file = new File(dir, "data.zip");
@@ -83,7 +88,7 @@ public class ProjectUtilities {
         }
     }
 
-    protected static void saveToFile(Project project, File file) throws Exception {
+    protected static void saveToFile(Project project, File file) throws IOException  {
         ZipOutputStream out = new ZipOutputStream(new FileOutputStream(file));
         try {
             Pool pool = new Pool();