Index: lams_common/src/java/org/lamsfoundation/lams/util/FileUtil.java
===================================================================
diff -u -r58477cd191e3bc278b06ec3e012c196aedd788dc -r623a8b69a67eb91d7e0a31c5f4d15c4fabb9aa6f
--- lams_common/src/java/org/lamsfoundation/lams/util/FileUtil.java	(.../FileUtil.java)	(revision 58477cd191e3bc278b06ec3e012c196aedd788dc)
+++ lams_common/src/java/org/lamsfoundation/lams/util/FileUtil.java	(.../FileUtil.java)	(revision 623a8b69a67eb91d7e0a31c5f4d15c4fabb9aa6f)
@@ -28,6 +28,7 @@
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
+import java.net.URLEncoder;
 import java.nio.channels.FileChannel;
 import java.util.Date;
 
@@ -528,4 +529,25 @@
 			}
 			return 0;
 		}
+
+		/**
+		 * Remove chars from a file name that may be invalid on a file system.
+		 * @param name
+		 * @return a filename that can be saved to a file system.
+		 */
+		public static String stripInvalidChars(String name) {
+			name = name.replaceAll("\\\\", "");
+			name = name.replaceAll("\\/", "");
+			name = name.replaceAll("\\:", "");
+			name = name.replaceAll("\\*", "");
+			name = name.replaceAll("\\?", "");
+			name = name.replaceAll("\\>", "");
+			name = name.replaceAll("\\<", "");
+			name = name.replaceAll("\\|", "");
+			name = name.replaceAll("\\#", "");
+			name = name.replaceAll("\\%", "");
+			name = name.replaceAll("\\$", "");
+			name = name.replaceAll("\\;", "");
+			return name;
+		}
 }
Index: lams_learning/src/java/org/lamsfoundation/lams/learning/export/ExportPortfolioConstants.java
===================================================================
diff -u -re53268b2dfab47fefe05312674eb1533f03acf7f -r623a8b69a67eb91d7e0a31c5f4d15c4fabb9aa6f
--- lams_learning/src/java/org/lamsfoundation/lams/learning/export/ExportPortfolioConstants.java	(.../ExportPortfolioConstants.java)	(revision e53268b2dfab47fefe05312674eb1533f03acf7f)
+++ lams_learning/src/java/org/lamsfoundation/lams/learning/export/ExportPortfolioConstants.java	(.../ExportPortfolioConstants.java)	(revision 623a8b69a67eb91d7e0a31c5f4d15c4fabb9aa6f)
@@ -42,6 +42,7 @@
 	public static final String MAIN_NOTEBOOK_FILENAME = "notebook_main.html";
 	public static final String EXPORT_LEARNER_PREFIX = "Portfolio";
 	public static final String EXPORT_TEACHER_PREFIX = "Class Portfolio";
+	public static final String EXPORT_TEMP_FILENAME = "export.zip";
 	public static final String HOST = getServerURL();
 	public static final String SUBDIRECTORY_BASENAME = "Activity"; //subdirectory for each activity is ActivityXX where XX is the activity Id
 	public static final String SUBDIRECTORY_NOTEBOOK_BASENAME = "Notebook";
Index: lams_learning/src/java/org/lamsfoundation/lams/learning/export/service/ExportPortfolioService.java
===================================================================
diff -u -re53268b2dfab47fefe05312674eb1533f03acf7f -r623a8b69a67eb91d7e0a31c5f4d15c4fabb9aa6f
--- lams_learning/src/java/org/lamsfoundation/lams/learning/export/service/ExportPortfolioService.java	(.../ExportPortfolioService.java)	(revision e53268b2dfab47fefe05312674eb1533f03acf7f)
+++ lams_learning/src/java/org/lamsfoundation/lams/learning/export/service/ExportPortfolioService.java	(.../ExportPortfolioService.java)	(revision 623a8b69a67eb91d7e0a31c5f4d15c4fabb9aa6f)
@@ -281,7 +281,8 @@
 		{
 		    throw new ExportPortfolioException("An error has occurred while zipping up the directory ", e);
 		}
-		return zipfileName;
+		int index = dirToPutZip.lastIndexOf(File.separator);
+		return (index > -1 ? dirToPutZip.substring(index+1) : dirToPutZip);
 	}
 	
 	/** @see org.lamsfoundation.lams.learning.export.service.IExportPortfolioService#doExport(Vector, Cookie[]) */
Index: lams_learning/src/java/org/lamsfoundation/lams/learning/export/service/IExportPortfolioService.java
===================================================================
diff -u -r8bd9b88a431c50cf5b0f64a8e48a9d2ccc748fda -r623a8b69a67eb91d7e0a31c5f4d15c4fabb9aa6f
--- lams_learning/src/java/org/lamsfoundation/lams/learning/export/service/IExportPortfolioService.java	(.../IExportPortfolioService.java)	(revision 8bd9b88a431c50cf5b0f64a8e48a9d2ccc748fda)
+++ lams_learning/src/java/org/lamsfoundation/lams/learning/export/service/IExportPortfolioService.java	(.../IExportPortfolioService.java)	(revision 623a8b69a67eb91d7e0a31c5f4d15c4fabb9aa6f)
@@ -102,7 +102,7 @@
 	 * 
 	 * @param filename
 	 * @param directoryToZip
-	 * @return
+	 * @return name of directory containing zipped up portfolio.
 	 */
 	public String zipPortfolio(String filename, String directoryToZip);
 	
Index: lams_learning/src/java/org/lamsfoundation/lams/learning/export/web/action/ExportDownloadServlet.java
===================================================================
diff -u -r5df048f46a93d1767286c6bb25773ec3d19d1aa0 -r623a8b69a67eb91d7e0a31c5f4d15c4fabb9aa6f
--- lams_learning/src/java/org/lamsfoundation/lams/learning/export/web/action/ExportDownloadServlet.java	(.../ExportDownloadServlet.java)	(revision 5df048f46a93d1767286c6bb25773ec3d19d1aa0)
+++ lams_learning/src/java/org/lamsfoundation/lams/learning/export/web/action/ExportDownloadServlet.java	(.../ExportDownloadServlet.java)	(revision 623a8b69a67eb91d7e0a31c5f4d15c4fabb9aa6f)
@@ -98,9 +98,17 @@
 	
 	private String constructAbsolutePath(String relativePath)
 	{
-	    return FileUtil.TEMP_DIR + File.separator + relativePath;
+		return FileUtil.TEMP_DIR + File.separator
+			+ getDirname(relativePath) + File.separator 
+			+ ExportPortfolioConstants.EXPORT_TEMP_FILENAME;
 	}
 	
+	private String getDirname(String path) 
+	{
+		int index = path.indexOf(File.separator);
+		return (index>0 ? path.substring(0, index) : path);
+	}
+	
 	private String getFilename(String path)
 	{
 		int index = path.lastIndexOf(File.separator);
Index: lams_learning/src/java/org/lamsfoundation/lams/learning/export/web/action/MainExportServlet.java
===================================================================
diff -u -r8373eb78b0931c5c0a21634563b759cab8299e7e -r623a8b69a67eb91d7e0a31c5f4d15c4fabb9aa6f
--- lams_learning/src/java/org/lamsfoundation/lams/learning/export/web/action/MainExportServlet.java	(.../MainExportServlet.java)	(revision 8373eb78b0931c5c0a21634563b759cab8299e7e)
+++ lams_learning/src/java/org/lamsfoundation/lams/learning/export/web/action/MainExportServlet.java	(.../MainExportServlet.java)	(revision 623a8b69a67eb91d7e0a31c5f4d15c4fabb9aa6f)
@@ -24,8 +24,10 @@
 /* $$Id$$ */	
 package org.lamsfoundation.lams.learning.export.web.action;
 
+import java.io.File;
 import java.io.IOException;
 import java.io.PrintWriter;
+import java.net.URLEncoder;
 
 import javax.servlet.ServletException;
 import javax.servlet.http.Cookie;
@@ -129,7 +131,7 @@
 		
 		if (portfolios!= null)
 		{
-			
+			exportFilename = FileUtil.stripInvalidChars(exportFilename);
 			exportTmpDir = portfolios.getExportTmpDir();
 				
 			exportService.generateMainPage(request, portfolios, cookies);	
@@ -143,8 +145,8 @@
 			CSSBundler bundler = new CSSBundler(request, cookies, exportTmpDir, exportService.getUserThemes());
 			bundler.bundleStylesheet();
 			
-			// zip up the contents of the temp export folder 
-			String zipFilename = exportService.zipPortfolio(exportFilename, exportTmpDir);
+			// zip up the contents of the temp export folder using a constant name
+			String exportZipDir = exportService.zipPortfolio(ExportPortfolioConstants.EXPORT_TEMP_FILENAME, exportTmpDir);
 /*			-- Used for testing timeout  change the export url in exportWaitingPage to  
 			-- String exportUrl = learning_root + "portfolioExport?" + request.getQueryString()+"&sleep=1800000";
 			-- to pause for 30 mins. 
@@ -158,23 +160,16 @@
 				}
 			}
 */			
-			//return the relative filelocation of the zip file so that it can be picked up in exportWaitingPage.jsp
+			// return the relative (to server's temp dir) filelocation of the 
+			// zip file so that it can be picked up in exportWaitingPage.jsp
 			PrintWriter out = response.getWriter();
-			out.println(returnRelativeExportTmpDir(zipFilename)); 
+			out.println(URLEncoder.encode(exportZipDir + File.separator + exportFilename, "UTF-8"));
 		}
 		else
 		{
 		    //redirect the request to another page.
 		}
 		
 	}
-	
 
-	private String returnRelativeExportTmpDir(String absolutePath)
-	{
-	    String tempSysDirName = FileUtil.TEMP_DIR;
-	    return absolutePath.substring(tempSysDirName.length()+1, absolutePath.length());
-	}
-	
-
 }