Originally Posted by jpt
Yeah -- I think it's any format that doesn't define pages itself that's buggy.
Even the ones that do are buggy since it returns to the start of the application defined page instead of the page you bookmarked which could be several pages later. Bookmarks are difficult to use for this reason.
One solution I suggested to Jinke was to store the zoom level with the page number and then set the zoom when it returned to go to the same place. This doesn't address the flaws in the page numbering but does allow it to work as expected for bookmarks.