Hmm yes, very annoying, this problem is. We're currently trying to unravel the mysterious source of this save as zip dilemma. In the meantime, we've disabled the save as zip option for visitors, meaning you won't be able to save other users' albums. You will only be able to save your own albums as a zip file. For a smoother zipping experience, try keeping the load light – save a maximum of 15 photos at a go.