Index: wp-admin/includes/media.php
===================================================================
--- wp-admin/includes/media.php	(revision 22925)
+++ wp-admin/includes/media.php	(working copy)
@@ -1325,7 +1325,7 @@
 	$form_fields = apply_filters( 'attachment_fields_to_edit', $form_fields, $post );
 
 	unset( $form_fields['image-size'], $form_fields['align'], $form_fields['image_alt'],
-		$form_fields['post_title'], $form_fields['post_excerpt'], $form_fields['post_content'],
+		$form_fields['post_title'], $form_fields['post_excerpt'],
 		$form_fields['url'], $form_fields['menu_order'], $form_fields['image_url'] );
 
 	$media_meta = apply_filters( 'media_meta', '', $post );