Uploading

When I try to upload a file I get this error on everything I try to upload.

Fatal error: Cannot redeclare class File_CSV_DataSource in /home/leaving thisblank/public_html/blog/wp-content/plugins/csv-importer/File_CSV_DataSource/DataSource.php on line 60

Any help would be great.

http://ww.wp.xz.cn/extend/plugins/csv-importer/