Repair PHP Bidding Script!!

I have a Online Auction PHP Script that i need some changes to be made on, the script is from AJ Auctions. The problem is that when i install the script everything is ok except when i try to register to make a test an SQL error message appears in the top of the page and this happens for most of the pages, also the system fails to send a verification email once the user has registered and some more other hings may be have to be changed. This should b a fair easy job for someone familliar with PHP!!!!