diff --git a/picture.php b/picture.php
index e736373ba..d5050abcd 100644
--- a/picture.php
+++ b/picture.php
@@ -944,6 +944,7 @@ $template->assign( 'ELEMENT_CONTENT', $element_content );
 
 if (isset($picture['next'])
     and $picture['next']['src_image']->is_original()
+    and $template->get_template_vars('U_PREFETCH') == null
     and strpos($_SERVER['HTTP_USER_AGENT'], 'Chrome/') === false)
 {
   $template->assign(
diff --git a/themes/default/template/picture.tpl b/themes/default/template/picture.tpl
index f41b573e3..debe06dd2 100644
--- a/themes/default/template/picture.tpl
+++ b/themes/default/template/picture.tpl
@@ -31,7 +31,7 @@ function changeImgSrc(url,typeSave,typeMap)
 		theImg.useMap = "#map"+typeMap;
 	}
 	jQuery('#derivativeSwitchBox .switchCheck').css('visibility','hidden');
-	jQuery('#derivativeChecked'+typeSave).css('visibility','visible');
+	jQuery('#derivativeChecked'+typeMap).css('visibility','visible');
 	document.cookie = 'picture_deriv='+typeSave+';path={/literal}{$COOKIE_PATH}{literal}';
 }
 (SwitchBox=window.SwitchBox||[]).push("#derivativeSwitchLink", "#derivativeSwitchBox");
@@ -42,7 +42,7 @@ function changeImgSrc(url,typeSave,typeMap)
 <div id="derivativeSwitchBox" class="switchBox">
   <div class="switchBoxTitle">{'Photo sizes'|@translate}</div>
   {foreach from=$current.unique_derivatives item=derivative key=derivative_type}
-  <span class="switchCheck" id="derivativeChecked{$derivative_type}"{if $derivative->get_type() ne $current.selected_derivative->get_type()} style="visibility:hidden"{/if}>&#x2714; </span>
+  <span class="switchCheck" id="derivativeChecked{$derivative->get_type()}"{if $derivative->get_type() ne $current.selected_derivative->get_type()} style="visibility:hidden"{/if}>&#x2714; </span>
   <a href="javascript:changeImgSrc('{$derivative->get_url()|@escape:javascript}','{$derivative_type}','{$derivative->get_type()}')">
     {$derivative->get_type()|@translate}<span class="derivativeSizeDetails"> ({$derivative->get_size_hr()})</span>
   </a><br>