Thats interesting that your having so many issues... I dont have that many machines/cards but mine have been very solid. All the tugging etc comments makes me wonder if your cards or machines are suffering from physical damage? Perhaps from poor handling during loadin/unloading or in transit in the truck? perhaps you are plugging your video lines directly into the cards every night and they have suffered some tugs/yanks... all speculation on my part obviously but it is very curious