When editing two comments, after having saved the first edit, it is impossible to save the second edit

Question

I have encountered a bug in the site Super User.

I make two comments :

1. Here is the Tadpole.
2. There is the Caterpillar.

To edit the comment 1, I click edit. In editing my comment, I add my new text :
The Tadpole becomes the Frog.

To edit the comment 2, I click edit. In editing my comment, I add my new text :
The Caterpillar becomes the Butterfly.

For the comment 1, I click Save Edits. This works.

For the comment 2, I click Save Edits. This has to work. But this does not work.

I have Firefox 28 on Mac.

I will reproduce the bug here.

Thank you for fixing this little bug, and keep up the good work !