I have been using the pre-cache images in the overview tab with no problem. But now i have 2000 images in the gallery and needed to cache an album at a time. So selected a sub album and clicked the little blue icon to pre-cache those images. and i get Zenphoto Error: the requested object was not found. Please go back and try again.
Also clicking the orange icon to refresh metadata gives me the same error.
But if I click on the album title and list all of the images, there is a a link there to pre-cache images. That link actually works and caches the images for that album.
Another way i've tried is to click on 'mass-edit all album data.' the pre-cache link at the bottom of the page works but it will only cache the images from the album at the bottom of the list of albums.
I have tried purging the cache and refreshing the database.
only problem i've had so far. i love zenphoto

Using version 1.1.5 [1219]