It isn’t username specific. Here’s a link to a page where we’re using the plugin.
http://www.wicproject.com/test-giveaway/
If you click “Enter”, the box pops up and we see three Follow boxes - no username. However other people do see the Twitter Handles - same page, same code, different users, different display.
It appears it might be browser specific - viewable on PC Firefox but not PC Chrome.