Hello dbarragan,
Thanks for reaching out to us!
This is definitely a strange issue to be having. Upon inspection, it looks like your hosting provider may be having difficulty handling the AJAX requests. If you try to load the next month directly (http://www.clubbritania.com/events/2014-11/) it loads fine.
Try opening a support request with your hosting provider and give them the specific content of the dialog box that shows up. Let them know it is occurring during an AJAX request and they should be able to assist you.
Let me know if this helps or if you have any further questions.
Thanks!