I cannot see shared photo stream in iPhoto ... Please help

I have tried all the solutions proposed in nearly similar problem; All the settings are ok.

All the version are ok (Iphoto, Lion)

I can see the photostream icon in RECENT part of the source sidebar but not under WEB or ANYTHING ELSE

I do not see the shared stream that function well on my 2 iphone 4s.

When I want to add photos to the photostream (either using ADD or SHARE) the option is only photostream not the shared ones neither offering me the possibility to add a new one...

Please help!!!