Problem with photos on stream...

Hello,

I have a big problem with the photos.
I explain it :

When a user post a photo (set to be visible for everybody), this photo is displayed on the stream. All the users can see this photo. BUT after a couple of minutes, or hours (I don't know exactly), the photos are not displayed anymore on the stream of other users. The user that posted the photo and the super users are the only members that can still see the photo...


Could it be due to amazon s3? But in this case why the photos are still displayed on their owners stream and on super users streams?


I have another question: I have configured amazon s3 in easysocial settings, but I think that the photos are not uploaded on amazon s3, because the bucket is still empty (see attachment). Is there something special to configure on amazon s3 website?

Thanks a lot