Q: photostream not working on my mac

Photos from my iphone sync to the cloud and to my ipad, but not my mac.  I have turned photostream on and off, but that doesnt seem to work,  I am running Mountain Lion and the latest version of iPhoto.

I have rebooted, etc.  Is there any other way to restart photostream besides turning it on or off.  I am comfortable doing things in Terminal.

Thanks