Window users can't register on my Elgg site

I've had reports from several of my friends who are using Windows can't register on my site. I have the register form on the front page and if that didn't work, I would redirect them to the /register view. There's no error visually or in the error logs. Has anyone experience this issue before?

Elgg & Server

  • Elgg 1.10
  • Nginx
  • Php 5.5