I ran into the same problem when I was trying to do this.  I tried saving it again using the "save as" menu option and found it was saved as a different type of csv file before.  Excel has 2 different types (CSV UTF-8, which is the original type of file it was saved as, and regular CSV).  Once I saved it as a regular .csv file, it worked.  Hope this helps someone having similar issues so that support doesn't have to get involved at all.