I checked the behaviour for `isImagePage` on a different installation of ZenPhoto (wete.org). I searched for `'e'`, what is quite stupid, but it leads to many results. ;-) I got 3 pages with albums, page 4 is mixed, page 5 ff. contains only images. Page 1 and 2 `isImagePage` returns `false` (correct behaviour). But on page 3 (only albums!) it returns `true`. In my first example (see above) there were only 2 pages of albums (page 1 pure, page 2 mixed), so I think, the error could be descriped as "works fine exept on the page BEFORE the first page with images".
Now I will install the nightly build and check this again.