Can I use CSV source files produced by the standard Salesforce Data Loader and vice versa?
Yes, you can. They are mostly compatible.
The file Import / Export feature supports standard Salesforce Data Loader file format.
So in most cases you can use CSV file previously generated by the Salesforce Data Loader or use the Data Loader to upload files generated by the Plugin.
There are still some differences in the format of CSV files supported by the Plugin and by the Salesforce Data Loader.
We are currently working to make it fully compliant.
Concider to set UTF-8 format in the Salesforce Data Loader settings.