@pmiller. Do you have any experience in programming in PHP? If you do, I would ask you to add some code to test something. However, before that, do you have access to your PH error log? It would be good to see if there are any PHP errors or warnings that are triggered.
I suspect the problem may be that your version of PHP (5.1.6) does not execute the class code properly. I do not have php 5.1.6 to test on, but it seems that there are other extensions that are also incompatible with it.