This is driving me batty. I updated to iCloud 2.0 and opened it up to try to figure out why my photos weren't syncing. I found that I could not click the Photo Stream options (nothing happens when I click it) and the Photo Stream was unchecked in the update. I click it, click Apply and close the window and when I reopen it, it is unchecked again! How do I fix this? This is on a Windows 7 pc, I do not use iPhoto (as I have seen the problem can be seen sometimes if you use that as well). Thanks!