diff --git a/test/concat_wu b/test/concat_wu
index 39f2005d54..26b47ec3cd 100644
--- a/test/concat_wu
+++ b/test/concat_wu
@@ -1,11 +1,11 @@
 <file_info>
     <name><INFILE_0/></name>
-    <url><DOWNLOAD_URL/><INFILE_0/></url>
+    <url><DOWNLOAD_URL/>0/<INFILE_0/></url>
     <md5_cksum><MD5_0/></md5_cksum>
 </file_info>
 <file_info>
     <name><INFILE_1/></name>
-    <url><DOWNLOAD_URL/><INFILE_1/></url>
+    <url><DOWNLOAD_URL/>/<INFILE_1/></url>
     <md5_cksum><MD5_1/></md5_cksum>
 </file_info>
 <workunit>
diff --git a/test/test.inc b/test/test.inc
index 3bb4c94983..80fb98621d 100644
--- a/test/test.inc
+++ b/test/test.inc
@@ -388,12 +388,11 @@ class Project {
 	    echo "\nsleeping for $time seconds";
 	    PassThru("sleep $time");
 	  }
-	PassThru("cp $source_dir/sched/cgi $
-this->project_dir/cgi/file_upload_handler$handler_num");
+	PassThru("cp $source_dir/sched/file_upload_handler $this->project_dir/cgi/file_upload_handler$handler_num");
       }
 
     //blocks until a file_upload_handler is running in the system, kills it and returns
-    function kill_file_upload_hanlder()
+    function kill_file_upload_handler()
       {
 	while(true)
 	  {
diff --git a/test/test_download_backoff.php b/test/test_download_backoff.php
index 4f45a585f2..de8efad84c 100644
--- a/test/test_download_backoff.php
+++ b/test/test_download_backoff.php
@@ -52,6 +52,6 @@
     $result->stderr_out = "APP: upper_case: starting, argc 1";
     $result->exit_status = 0;
     $project->check_results(2, $result);
-    $project->compare_file("uc_multiple_download_wu_0_0", "uc_correct_output");
-    $project->compare_file("uc_multiple_download_wu_1_0", "uc_correct_output");
+    $project->compare_file("uc_wu_0_0", "uc_correct_output");
+    $project->compare_file("uc_wu_1_0", "uc_correct_output");
 ?>
diff --git a/test/test_mdownload_backoff.php b/test/test_mdownload_backoff.php
new file mode 100644
index 0000000000..9e9951881b
--- /dev/null
+++ b/test/test_mdownload_backoff.php
@@ -0,0 +1,58 @@
+#! /usr/local/bin/php
+<?php
+//This tests the exponential backoff mechanism on the client in case of downloadURLs going down. in this case multiple URLS stay up while one goes down. 
+//This test is not automated. It has to be run, and then client.out (in the host directory) must be looked at to examine wether everything is working correctly.    
+    include_once("test.inc");
+
+    $project = new Project;
+    $user = new User();
+    $host = new Host($user);
+
+    $app = new App("upper_case");
+    $app_version = new App_Version($app);
+
+    // the following is optional (makes client web download possible)
+    $core_app = new App("core client");
+    $core_app_version = new App_Version($core_app);
+    $project->add_app($core_app);
+    $project->add_app_version($core_app_version);
+
+    $project->add_user($user);
+    $project->add_app($app);
+    $project->add_app_version($app_version);
+
+    $project->install();      // must install projects before adding to hosts
+
+    $host->log_flags = "log_flags.xml";
+    $host->add_project($project);
+    $host->install();
+
+    echo "adding work\n";
+
+    $work = new Work($app);
+    $work->wu_template = "uc_multiple_download_wu";
+    $work->result_template = "uc_result";
+    $work->nresults = 2;
+    $work->delay_bound = 10;
+    array_push($work->input_files, "input");
+    $work->install($project);
+
+    $project->start_feeder();
+    //delete the download_dir0 immediately 
+    $project->delete_downloaddir(null, 0);
+    $project->delete_downloaddir(null, 1);
+    $project->delete_downloaddir(null, 2);
+  
+    $pid = $host->run_asynch("-exit_when_idle");
+    $status = 0;
+    //wait until the host has stopped running
+    pcntl_waitpid($pid,$status,0);
+    $project->stop();
+
+    $result->state = RESULT_STATE_DONE;
+    $result->stderr_out = "APP: upper_case: starting, argc 1";
+    $result->exit_status = 0;
+    $project->check_results(2, $result);
+    $project->compare_file("uc_multiple_download_wu_0_0", "uc_correct_output");
+    $project->compare_file("uc_multiple_download_wu_1_0", "uc_correct_output");
+?>
diff --git a/test/test_upload_backoff.php b/test/test_upload_backoff.php
new file mode 100644
index 0000000000..8d9225aec1
--- /dev/null
+++ b/test/test_upload_backoff.php
@@ -0,0 +1,58 @@
+#! /usr/local/bin/php
+<?php
+//This tests the exponential backoff mechanism on the client in case of downloadURLs going down
+//This test is not automated. It has to be run, and then client.out (in the host directory) must be looked at to examine wether everything is working correctly.    
+    include_once("test.inc");
+
+    $project = new Project;
+    $user = new User();
+    $host = new Host($user);
+
+    $app = new App("upper_case");
+    $app_version = new App_Version($app);
+
+    // the following is optional (makes client web download possible)
+    $core_app = new App("core client");
+    $core_app_version = new App_Version($core_app);
+    $project->add_app($core_app);
+    $project->add_app_version($core_app_version);
+
+    $project->add_user($user);
+    $project->add_app($app);
+    $project->add_app_version($app_version);
+
+    $project->install();      // must install projects before adding to hosts
+
+    $host->log_flags = "log_flags.xml";
+    $host->add_project($project);
+    $host->install();
+
+    echo "adding work\n";
+
+    $work = new Work($app);
+    $work->wu_template = "uc_wu";
+    $work->result_template = "uc_result";
+    $work->nresults = 2;
+    $work->delay_bound = 10;
+    array_push($work->input_files, "input");
+    $work->install($project);
+
+    $project->start_feeder();
+    //delete the download_dir immediately 
+    $project->remove_file_upload_handler()
+    $pid = $host->run_asynch("-exit_when_idle");
+  
+    //reinstall download_dir after 100 seconds
+    $project->reinstall_file_upload_handler(20,null);
+    $status = 0;
+    //wait until the host has stopped running
+    pcntl_waitpid($pid,$status,0);
+    $project->stop();
+
+    $result->state = RESULT_STATE_DONE;
+    $result->stderr_out = "APP: upper_case: starting, argc 1";
+    $result->exit_status = 0;
+    $project->check_results(2, $result);
+    $project->compare_file("uc_wu_0_0", "uc_correct_output");
+    $project->compare_file("uc_wu_1_0", "uc_correct_output");
+?>