Unable to sort and delete

Prerequsit:
* Have Drupal 7 Installed, with no contributed modules enabled.

How to recreate:
1. Create a new article and add some pictures (sort them if you like, works fine here), and fill in mandatory fields.
2. Save the article.
3. Edit the article.
4. Try to delete an image.
Result:
It doesn't work

5. Sort the pictures and save.
Result:
It's sorted as it was from the beginning.

Hope it's not a big deal to fix!
Best regards
// Tim, Sweden