Hello ! i have the same problem with sections (in book style).
I use \markright for changing the section title in the header - TWICE, just before and after the \section. Otherwise [just with \markright{..} \section{..}] (only!) the first page with the new section has the long title in the fancyheader! My "solution": \markright{short} \section{looooooooooooooooooooooooooooooooooong title} \markright{short} The long title will appear in the TOC. But i think that this will cause problems when the section starts on a new page... I haven't tried it with chapters; maybe there is a problem that the short title appears on the page before the new chapter (because this always uses a new page)!? For chapters the caommand is not \markright but \markboth{short CHAPTER name}{section name}. I use Lyx 1.3.7 (German) but i can't find "Insert>Short Title". But it seems that the code created is "\section[short]{looooooooong title}", isn't it? The short title will appear in the TOC in this case. Best wishes, Marco > > Try to use instead Insert>Short Title to specify the shorter version > > of the chapter title. > > Actually, I spoke too soon. This solution does sort my header problem, but > it creates another one. In the toc, I then get the short title, but I > would like the full title to appear. -- Der GMX SmartSurfer hilft bis zu 70% Ihrer Onlinekosten zu sparen! Ideal für Modem und ISDN: http://www.gmx.net/de/go/smartsurfer