I see the problem on both IE and Firefox. I don’t think it is a Firefox issue. I think the ajax script does not update properly because when you click on the February link and you click refresh, then the correct events come up. Do you use CloudFlare? If so, you can try disabling it and see if this solves the issue.
It works for me in Internet Explorer, but neither Firefox or Chrome. The only way it works is if I refresh the page, but my users are not going to know that. 🙁 The URL changes to the correct month, but moving it back or forward keeps it on the current month, or if I type in a URL for the next month, it’ll work, but if I try to go forward with the navigation, it goes back to the current month.
I agree with kaniamea that this fully appears to be an Ajax issue. Furthermore it appear to be related to your theme. I notice that your theme is not outputting the body_class() along with it’s body tag. This is something that our plugin now relies on to work, as it is really a standard part of WP themes that all themes should have if they want to support plugins. I bet if you add that function call, which is documented within the WP Codex, all will be well. You might even be able to convince your theme developer to do it for you. I hop[e that helps. Cheers!
I have a wp development site with the Events plugin installed and I’m having the same issue I’m seeing complained about – can’t get future or past months to display in my calendar! I do have the body class in the header. When I click on Next or Previous in the calendar display it just jumps me to the page where I have my events list displayed.