Why photo stream is not working in my iPhone 4s with ios 6?

Since i update my iphone 4s to ios6, the photo stream function does not work.

After the ios 6 upgrade i checked that my photo stream photos, where there both in iphone and imac (i used iphoto, now i am using aperture..see comment below). Yesterday i delete the pictures from my photo stream and i tried to take new pictures to upload but all my attempts were failing.

Specifically, I have full battery and i am connected to wi-fi. I have the photo stream function "on", in the icloud settings, and i take a picture with my camera. I close the camera application and i go to the photo application to see this picture in "my photo stream". There is no picture there.

I have tried several things either from apple's trouble shooting guides or from several related discussions in forums, like opening and closing photo stream in iphone and imac. I reset photo stream from icloud and i even delete and recreate my icloud account. I closed the photo stream function both in my imac and iphone and i restarted them, but again no result. I hard reset the iphone and re-open photo stream

I have checked that i use the same icloud account and it is correct.

Another tip is that i recently upgrade Aperture to 3.4 in order to support photo stream. Since then i was using iphoto. The strange thing, is that after the upgrade, i lost the photo stream function in iphoto and i have it only in Aperture. In Aperture, I was able to see the photos i had photo streamed before the upgrade to ios 6

Furthermore, i tried to make a share photo stream and i shared a picture with my email address. I went to aperture where i can see the new shared photo stream folder but is is empty. In my iphone, i find the shared folder with the picture.

I really dont know what else to do because i have tried anything possible and i have search the whole web for a solution

Please help

thanks!