I used an 18 camera 12DCV power box. Not sure of the mA's on it, but I've never had this same problem with any of the other systems I used the same power supply on. Not saying that it's not the problem, just haven't had the fading issue before. The one thing I did do different on this system is split the VGA monitor using a VGA splitter/transformer. The only difference I noticed in that was a slight decrease in resolution on both monitors.
I'll be going to this job on Sunday afternoon and will first look at the connections and if the cameras have any settings on them for flicker. I don't remember any setting switches though.
And if that doesn't work, I'll try replacing one of the cameras with a new one and see if that makes a difference.
Thanks again for all the comments and suggestions....I really do appreciate it all.