Montezuma and The Events Calendar

Hi Guys

Newbie here in all senses! I am starting to look at creating a new website for our non profit sea sports club.

I love the Montezuma theme and think it is ideal for the website I am thinking about. We also have multiple events calendars, which "the events calendar" does very well, and better than most other plugins i have tried.

The problem I have is that the events calendar refuses to render at all with this theme. If i choose Default events template in the events calendar settings all styles / css seems to fail and I end up with the page displaying just unformatted text as per image attached. If i choose default page template, then some style is added but still no table buttons or anything is shown (this is how it is currently set up at http://www.orssc.asn.au/test/events/category/whats-on/)

Can anyone give me some pointers as to where to look to resolve this issue. I am useless or worse at PHP and css, but can hack around a little. I have tried twenty twelve / thirteen and it works with them.

thanks in advance

Steve