Apple TV 2 Pictures Issues

[mprofit]

I'm having some issues with my Apple TV and pictures, specifically the Screensaver and Photo Stream features.

Before I got my current MacBook Pro, I was able to use pictures streamed from my computer as my screensaver, even with my computer turned off. However, since I bought this computer I haven't been able to do that. I've gone through the Photo Sharing Preferences in iTunes and have selected the photo albums I want to stream to the Apple TV, have turned Home Sharing on on the Apple TV and on iTunes, but the option to use these photos as my screen saver doesn't appear in the Apple TV preferences. Any ideas why?

Also, Photo Stream has never worked for my on Apple TV since iCloud debuted. It's not as big of a deal as the screensaver not working, but it's a feature that would be nice if it worked for me. I've "dumped" several photos from iPhoto into my Photo Stream on my computer, and have turned on Photo Stream both on my Mac and on Apple TV. Yet when I try to access them on Apple TV, no photos appear (it even gives me an error message saying that I don't have any photos in my Photo Stream). The only possibility I can imagine is that Photo Stream is limited only to photos taken from an iPad/iPhone, but really that restriction to me seems unlikely.

Would appreciate any help on either (or both) issues. Thanks.