Indeed Klaus the licence was not a the server because we added it on the old server that we used. Thanks, Klaus and Jarredja, for helping on a silly problem and sorry to have bothered you.
I have the watermark in the krpano viewer when I use iphone/ipad. However I added the krpano.license, krpanoiphone.license.js and krpanoiphone.js in the directory of the krpano.swf. You can see an example here by using an iphone or an ipad : http://www.myvisit360.com/entreprise/iloha-seaview-hotel