Correct PHP bugs in a adserver script

I bought a software from a company to use as adserver. Unfortunately, it has many bugs and customer support is terrible. I am looking for a PHP programmer that can work with me to remove the bugs as I can test some aspects of the software. This is an ongoing project. Right now, I don't know all the bugs or how long it will take for you to finish but I prefer to work continuously with a single programmer on this job. We will work in installments. I will explain a problem, you will tell me the milestone/hours you want to fix it, then I send milestone and you start. Then , I continue testing the software and show you another bug. And the job continues...It is an ongoing work to debug until I can get a viable product to use. I will give you access to my server and a demo to see how the script should work. Very flexible terms but I want to work with one person. We will use TimeTracker application for the job. EXAMPLE Attached is a video showing one of the bugs. When a person registers, the website is supposed to show a message saying that you should confirm your email. It will then send an email to the address you used to register. Instead it shows a white screen and does not send the email.