Image windows multi-pages problem

[Renaud]

Hello,
I've got problem with the image uploader :

1/ after the upload, the window freeze like this :

If I go out of the post editor and come back, the picture is there.

2/ if I have more than 5 images, the multi-pages is not working :

so I can not insert the picture with the link, I must find the URL and go in the code of the post.

Thanks

[Renaud]

And the buttons insert, cover image and delete are not working.
How can I manually define the cover image ?

[Renaud]

OK, I find it in pages.php. But it's not the easiest way...