diff upload_image.module
first is the original code
second is the modifications

134,136c135,137
<           if ($teaser) {
<             $node->content['upload_images'] = array(
<               '#value' => theme('upload_images_teaser', $thumbnails),
---
>         if ($teaser) {
>             $node->content['upload_image'] = array(
>               '#value' => theme('upload_image_teaser', $thumbnails),
141,142c142,143
<             $node->content['upload_images'] = array(
<               '#value' => theme('upload_images_body', $thumbnails),
---
>             $node->content['upload_image'] = array(
>               '#value' => theme('upload_image_body', $thumbnails),
265c266
< function theme_upload_images($list) {
---
> function theme_upload_image($list) {