diff --git a/checkin_notes b/checkin_notes
index 604c60b260..59aa0ed0fe 100644
--- a/checkin_notes
+++ b/checkin_notes
@@ -11559,3 +11559,10 @@ David  21 Nov 2007
 
     html/inc/
         forum.inc
+
+David  21 Nov 2007
+    - user web: fix bug in user filter; fixes #505
+
+    html/user
+        forum_edit_forum_preferences_action.php
+        forum_edit_forum_preferences_form.php
diff --git a/html/user/edit_forum_preferences_action.php b/html/user/edit_forum_preferences_action.php
index 10ad3e8e18..e0097cea78 100644
--- a/html/user/edit_forum_preferences_action.php
+++ b/html/user/edit_forum_preferences_action.php
@@ -118,7 +118,7 @@ if ($add_user_to_filter){
 $ignored_users = get_ignored_list($user);
 for ($i=0;$i<sizeof($ignored_users);$i++){
     if ($_POST["remove".trim($ignored_users[$i])]!=""){
-        $other_user = BoincUser::lookup_id($user_to_add);
+        $other_user = BoincUser::lookup_id($ignored_users[$i]);
         if (!$other_user) {
             echo "No such user: $other_user";
         } else {
diff --git a/html/user/edit_forum_preferences_form.php b/html/user/edit_forum_preferences_form.php
index 13bb8ee2ee..3fb04b0539 100644
--- a/html/user/edit_forum_preferences_form.php
+++ b/html/user/edit_forum_preferences_form.php
@@ -120,10 +120,11 @@ row2(
 
 $filtered_userlist = get_ignored_list($user);
 for ($i=0; $i<sizeof($filtered_userlist); $i++){
-    if ($filtered_userlist[$i] != ""){
-        $filtered_user = BoincUser::lookup_id($filtered_userlist[$i]);
-        if ($filtered_user) {
-            echo "missing user $filtered_userlist[$i]";
+    $id = (int)$filtered_userlist[$i];
+    if ($id) {
+        $filtered_user = BoincUser::lookup_id($id);
+        if (!$filtered_user) {
+            echo "Missing user $id";
             continue;
         }
         $forum_filtered_userlist .= "<input type =\"submit\" name=\"remove".$filtered_user->id."\" value=\"Remove\"> ".$filtered_user->id." - ".user_links($filtered_user)."<br>";