diff --git a/TODO b/TODO
index 2515386..e245951 100755
--- a/TODO
+++ b/TODO
@@ -1,10 +1,8 @@
 * i18n
-* handle negative amounts
 
 inc/Invoices.class.php :
 ========================
 * Modify store() method to handle storage
-* Modify load() method to handle JOIN
 * Modify load() method to handle complex queries (such as WHERE date < DATE_1 AND date > DATE_2)
 * Cache
 
diff --git a/inc/User.class.php b/inc/User.class.php
index 4a94ecd..3a2f38d 100644
--- a/inc/User.class.php
+++ b/inc/User.class.php
@@ -100,10 +100,10 @@ class User extends Storage {
     }
 
     // Check wether a user already exists or not 
-    // (a user = aunique login and display_name)
+    // (a user = a unique login and display_name)
     // =========================================
     public function isUnique() {
-        if(count($this->load(array('login'=>$this->login))) == 0 && count($this->load(array('display_name'=>$this->display_name)))) {
+        if($this->load(array('login'=>$this->login)) === false && $this->load(array('display_name'=>$this->display_name)) === false) {
             return true;
         }
         else {
diff --git a/index.php b/index.php
index 390540e..b7510a1 100644
--- a/index.php
+++ b/index.php
@@ -365,15 +365,24 @@
             break;
 
         default:
-            $users_list = new User();
-            $users_list = $users_list->load();
+            // Display cached page in priority
+            if($cache = $tpl->cache('index', $expire_time = 600, $cache_id = NULL)) {
+                echo $cache;
+            }
+            else {
+                $users_list = new User();
+                $users_list = $users_list->load();
 
-            $invoices_list = new Invoice();
-            $invoices_list = $invoices_list->load();
+                $invoices_list = new Invoice();
+                $invoices_list = $invoices_list->load();
 
-            $tpl->assign('users', secureDisplay($users_list));
-            $tpl->assign('invoices', secureDisplay($invoices_list));
+                $tpl->assign('users', secureDisplay($users_list));
+                $tpl->assign('invoices', secureDisplay($invoices_list));
 
-            $tpl->draw('index');
-            break;
+                // Cache the page (1 month to make it almost permanent and only regenerate it upon new invoice)
+                $tpl->cache('index', 108000, NULL);
+
+                $tpl->draw('index');
+                break;
+            }
     }
diff --git a/tpl/css/style.css b/tpl/css/style.css
index a3b922a..6212b21 100644
--- a/tpl/css/style.css
+++ b/tpl/css/style.css
@@ -95,6 +95,10 @@ input[type=submit] {
     padding: 0.1em;
 }
 
+#detailed_summary {
+    margin-top: 2.5em;
+}
+
 #connexion_form {
     margin: auto;
     width: 67%;
@@ -122,16 +126,8 @@ textarea#what {
     width: 75%;
 }
 
-#list_expenses tr:hover {
-    background-color: #00bd00;
-}
-
-#balance_table tr:not(:first-child):hover * {
-    background-color: #00bd00;
-}
-
-.highlight_td {
-    background-color: #00bd00;
+#list_expenses tr:hover, #balance_table tr:not(:first-child):hover *, .highlight_td {
+    background-color: green;
 }
 
 #user_connected {
diff --git a/tpl/index.html b/tpl/index.html
index 82d7b33..8fe48ad 100755
--- a/tpl/index.html
+++ b/tpl/index.html
@@ -27,27 +27,31 @@
 <div id="detailed_summary">
     <h2>Detailed list of bills for last month</h2>
 
-    <table id="list_expenses">
-        <tr>
-            <th>Date</th>
-            <th>Paid by</th>
-            <th>Users in</th>
-            <th>Amount</th>
-            <th>What ?</th>
-            <th>Edit</th>
-            <th>Delete</th>
-        </tr>
-        {loop="invoices"}
+    {if condition="count($invoices)>1"}
+        <table id="list_expenses">
             <tr>
-                <td>{$value->getDate()}</td>
-                <td>{$value->getBuyer()->getDisplayName()}</td>
-                <td>{$value->getUsersIn()}</td>
-                <td>{$value->getAmount()}</td>
-                <td>{$value->getWhat()}</td>
-                <td><a href="index.php?do=edit_invoice&id={$value->getId()}">Edit</a></td>
-                <td><a href="index.php?do=delete_invoice&id={$value->getId()}">Delete</a></td>
+                <th>Date</th>
+                <th>Paid by</th>
+                <th>Users in</th>
+                <th>Amount</th>
+                <th>What ?</th>
+                <th>Edit</th>
+                <th>Delete</th>
             </tr>
-        {/loop}
-    </table>
+            {loop="invoices"}
+                <tr>
+                    <td>{$value->getDate()}</td>
+                    <td>{$value->getBuyer()->getDisplayName()}</td>
+                    <td>{$value->getUsersIn()}</td>
+                    <td>{$value->getAmount()}</td>
+                    <td>{$value->getWhat()}</td>
+                    <td><a href="index.php?do=edit_invoice&id={$value->getId()}">Edit</a></td>
+                    <td><a href="index.php?do=delete_invoice&id={$value->getId()}">Delete</a></td>
+                </tr>
+            {/loop}
+        </table>
+    {else}
+        <p class="center">No bills added.</p>
+    {/if}
 </div>
 {include="footer"}