When the new exporter produces a TeX file that contains unicode characters, Emacs tries to save this file with coding systems `undecided-unix´ and `iso-latin1-unix´, both of which don't work of course (and the latter would likely be wrong for some characters). While it should be possible to change the default coding systems to use, it would certainly be better if the exporter took note of the
\usepackage[utf8]{inputenc} and alter the coding system for saving the TeX file accordingly. Regards, Achim.