Index: wp-admin/users.php
===================================================================
--- wp-admin/users.php	(revision 17001)
+++ wp-admin/users.php	(working copy)
@@ -357,7 +357,7 @@
 
 <form action="" method="post">
 
-<?php if ( $wp_list_table->has_items() ) : ?>
+<?php if ( $wp_list_table->has_items_or_search() ) : ?>
 
 <p class="search-box">
 	<label class="screen-reader-text" for="user-search-input"><?php _e( 'Search Users' ); ?>:</label>
Index: wp-admin/edit-comments.php
===================================================================
--- wp-admin/edit-comments.php	(revision 17001)
+++ wp-admin/edit-comments.php	(working copy)
@@ -220,7 +220,7 @@
 
 <form id="comments-form" action="" method="post">
 
-<?php if ( $wp_list_table->has_items() ) : ?>
+<?php if ( $wp_list_table->has_items_or_search() ) : ?>
 
 <p class="search-box">
 	<label class="screen-reader-text" for="comment-search-input"><?php _e( 'Search Comments' ); ?>:</label>
Index: wp-admin/includes/class-wp-list-table.php
===================================================================
--- wp-admin/includes/class-wp-list-table.php	(revision 17002)
+++ wp-admin/includes/class-wp-list-table.php	(working copy)
@@ -169,6 +169,18 @@
 	}
 
 	/**
+	 * Whether there any items or a search is performed
+	 *
+	 * @since 3.1.0
+	 * @access public
+	 *
+	 * @return bool
+	 */
+	function has_items_or_search() {
+		return !empty( $_REQUEST['s'] ) || $this->has_items();
+	}
+
+	/**
 	 * Message to be displayed when there are no items
 	 *
 	 * @since 3.1.0
Index: wp-admin/upload.php
===================================================================
--- wp-admin/upload.php	(revision 17001)
+++ wp-admin/upload.php	(working copy)
@@ -206,7 +206,7 @@
 
 <form id="posts-filter" action="" method="post">
 
-<?php if ( $wp_list_table->has_items() ) : ?>
+<?php if ( $wp_list_table->has_items_or_search() ) : ?>
 
 <p class="search-box">
 	<label class="screen-reader-text" for="media-search-input"><?php _e( 'Search Media' ); ?>:</label>
Index: wp-admin/plugins.php
===================================================================
--- wp-admin/plugins.php	(revision 17001)
+++ wp-admin/plugins.php	(working copy)
@@ -377,7 +377,7 @@
 
 <form method="post" action="">
 
-<?php if ( $wp_list_table->has_items() ) : ?>
+<?php if ( $wp_list_table->has_items_or_search() ) : ?>
 
 <p class="search-box">
 	<label class="screen-reader-text" for="plugin-search-input"><?php _e( 'Search Plugins' ); ?>:</label>
Index: wp-admin/edit.php
===================================================================
--- wp-admin/edit.php	(revision 17001)
+++ wp-admin/edit.php	(working copy)
@@ -242,7 +242,7 @@
 
 <form id="posts-filter" action="" method="get">
 
-<?php if ( $wp_list_table->has_items() ) : ?>
+<?php if ( $wp_list_table->has_items_or_search() ) : ?>
 
 <p class="search-box">
 	<label class="screen-reader-text" for="post-search-input"><?php echo $post_type_object->labels->search_items; ?>:</label>
Index: wp-admin/link-manager.php
===================================================================
--- wp-admin/link-manager.php	(revision 17001)
+++ wp-admin/link-manager.php	(working copy)
@@ -76,7 +76,7 @@
 
 <form id="posts-filter" action="" method="post">
 
-<?php if ( $wp_list_table->has_items() ) : ?>
+<?php if ( $wp_list_table->has_items_or_search() ) : ?>
 
 <p class="search-box">
 	<label class="screen-reader-text" for="link-search-input"><?php _e( 'Search Links' ); ?>:</label>
Index: wp-admin/themes.php
===================================================================
--- wp-admin/themes.php	(revision 17001)
+++ wp-admin/themes.php	(working copy)
@@ -146,7 +146,7 @@
 
 <h3><?php _e('Available Themes'); ?></h3>
 
-<?php if ( $wp_list_table->has_items() ) : ?>
+<?php if ( $wp_list_table->has_items_or_search() ) : ?>
 
 <form class="search-form filter-form" action="" method="get">