I tested the D7 version.
1) Install and turn on the Feeds Tamper module
2) Go to admin/structure/feeds and select tamper for the importer you want to apply it. Add the plugin explode for the multiple value fields
3) Make sure to have separator to be "," instead of ", " (there's an extra space after , ) when you export from either CVS or services views. This is important, because it'll break file enclosure file handling.