I have had this interference happen in the past. I had some nutradip trimeters on all of my reservoirs. I bought one of the early style Lumatek digital ballasts (when they were silver) to test out. As soon as the lights would come on the meters would start reading gibberish, really high numbers that constantly changed. If I unplugged the lumatek ballast the meters would resume normal operation.
The early ballasts emitted a ton of RFI and that can cause unshielded electronics to misbehave. If your ballast does emit RFI and you have cable internet or TV, it is possible for your ballast to interfere with other cable customers that are on your local cable loop. If this happens you will get a knock on the door when they determine the RFI is coming from your home.