Visual WYSIWYG: Pages of the visual remain untranslated when database is very slow

When scrolling through the visual with the databes being slow / long request times, parts/pages of the right visual may remain untranslated. The suspected reason lies in the SegmentMapping store: It may marks pages as loaded that are in fact not yet loaded (maybe due to timeouts). IMPORTANT: This is just a guess, so the "real" reason might be different