when reopen a impress file got wrong layout

[huqitu du]

hi ,
    when I use a vertical text layout in a impress and save the file and
when reopen the file, the layout will be horizontal, why? and how to fix
this problem.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/libreoffice/attachments/20120504/9c0af2b1/attachment.html>