TinyMCE is broken

After switching hosting server, the tinyMCE in the post editing screen does not fire up. Here is the message of the console.

As you can see, wp-tinymce.php seems to fail.

So far, I’ve tried :

• chmoding 777 (just to be sure) all the js/tinymce content
• reuploading the entire wp-include, forcing file replacement changing
• the header from javascript to json (here are the 3 tries i did):

try1:

header('Content-Type: application/x-javascript; charset=UTF-8');

try2:

header('Content-Type: application/json; charset=UTF-8');

try3:

header('Content-type: application/json');

In Firefox ‘s firebug extension, the message is “illegal character”
and when i open the file from within firebug, instead of seeing the code, all chars are messed up. But in my IDE, the php code looks correct.

Any other idea? Would it be a server misconfiguration?