(add-to-list 'org-latex-classes
'("beamer"
"
\\makeatletter\\let\\ifGm@compatii\\relax\\makeatother
\\documentclass\[t]{beamer\}"
("\\section\{%s\}" . "\\section*\{%s\}")
("\\subsection\{%s\}" . "\\subsection*\{%s\}")
("\\subsection\{%s\}" . "\\subsection*\{%s\}")
))
Maybe, I missed something.
Thanks
M