Trouble with showing articles

Hello, I've just bought this extension and installed it without a problem. The only thing is that I think that it's conflicting with my website. I am running JReviews and want to use the custom properties extension to search through the reviews. When you go to view a restaurant etc I get a server error. Here is my website www.rateitforkids.com

I know that these two extensions work with each other because there is another website with the same set up ( www.gmkids.co.uk ).

Please can anybody help??

As much as we'd like to help, there's little that we can do or say. All we get when visiting that URL is a blank page. No errors, no hints.
We only see the server is answering with a 500 error.

Of course the server has been configured not so show errors to the visitors, so you need to look a the log *files* and start from there.