Ok, it appears that your php configuration didn't allow for the uploaded file to be read the way the code was setup. This is a bug that needs to be patched for anyone else that runs into this problem, so I'm moving this to the bugs forums. I've fixed your site.

If anyone else runs into this problem, edit admin/importstyle2.php. Line 60 looks like this:

Code
$file = file_get_contents($style_temp);

That, needs to be changed to this:

Code
move_uploaded_file($style_temp,"{$config['FULL_PATH']}/styles/import.txt");
$file = file_get_contents("{$config['FULL_PATH']}/styles/import.txt");
unlink("{$config['FULL_PATH']}/styles/import.txt");