Define a paragraph with grey backgroun 10 % and choos surrounding lines for that paragraph. They are not to be seen. If you choose ap page sourroundig bei a grey margin, suddenly there are some lines in that margin. text an paragraphs are comming from 3.3.2. If you had saved the document with the missing marging under 3.4 and tried to read it in again with 3.3.2 the margins ar not missing or destructed.
*** Bug 36826 has been marked as a duplicate of this bug. ***
Cedric, could you please have a look? Note that the duplicate bug 36826 has more clear description.
Cedric fixed this by http://cgit.freedesktop.org/libreoffice/writer/commit/?h=libreoffice-3-4&id=cec2e2a1272d79b138cb190dcca68337b866cde6