I've just noticed -- after exporting an org file using the beamer backend, two hidden files are left in the directory. They both contain LaTeX code, so I'm quite sure they're coming from the export.
.fuse_hidden000001c000000001: ~~ \relax \providecommand\hyper@newdestlabel[2]{} \providecommand\HyperFirstAtBeginDocument{\AtBeginDocument} \HyperFirstAtBeginDocument{\ifx\hyper@anchor\@undefined \global\let\oldcontentsline\contentsline \gdef\contentsline#1#2#3#4{\oldcontentsline{#1}{#2}{#3}} ~~ ... And so on, for 90 lines .fuse_hidden000001c100000002: ~~ \BOOKMARK [2][]{Outline0.1}{``Lifted''}{}% 1 \BOOKMARK [2][]{Outline0.2}{``Lifted''\040sounds}{}% 2 ~~ Unlike the other LaTeX temporary files, these are not cleaned up after the export. Bug? hjh