Dear Hendri, Thanks for your code : 1. \makeatletter 2. \let\old@pd@twocolumn\pd@twocolumn 3. \def\pd@twocolumn[#1]#2#3{% 4. \old@pd@twocolumn[#1]{\raggedright#2}{\raggedright#3}% 5. } 6. \makeatother It works very fine but to cope with my presentations I had just change \def by \long\def in line 3. Best regards, Patrice MEGRET