marketpress import not working

I am trying to import a CSV file via the importer that is embedded in the MarketPress plugin. I select the file and click 'import'. The screen refreshes and says "Please be patient as this may take a while. Ready?" and there is another 'import' button.

I click that button and the screen refreshes, but nothing uploads. I am trying to upload just a small sample of my items (so that I can be sure that I have things configured properly when they are imported), so it shouldn't take very long to upload.

I have a quick video of what happens at the address below:

Thank you for your help.