Treehorn

I have a 18 path 12 v power supply box (1x 120v to 18x 12v). same as shown here http://www.ayagroup.com/product.php?productid=17140 I am getting video interference from this power supply. If I run my cameras off of the 12v on my handheld tester I do not get interference. I have tried two differnt style cables to connect the camera to the power supply 2-wire LVT cable and CAT-5. I was only using 5 feet of cable for testing and the power coming out of the power supply and the cable was arount 12.25v. It it likely that the power supply is bad? or was I doing something wrong? Thanks.

Thanks.