French accented characters not saving to database
Both suggested solutions above are good things to check when trying to solve this problem. 

In my particular case, using the fgetcsv command. It silently chokes on files that are not UTF-8 encoded and contains accented characters. To fix this problem I had to implement the file read function as follows:

while (($line = fgets($file_handle)) !== FALSE) {
  // Ensure the line we read is encoded properly
  $value = mb_check_encoding($line, 'UTF-8') ? $line : utf8_encode($line);
  $data = str_getcsv($value);
  // process the data as normal
}


This fixed my issue.