Had an old H'bird Matrix 17 that was given to me as a gift in 2004, it died in 2009. I found a similar, more modern version 1 year ago @ 50% off that used the same console mount but a different transducer....a 728 series I believe. Anyhow I installed the new transducer exactly as the instructions indicated (distance from the lower unit, angle to hull, etc). For the first time, late last week this new unit started acting up on while I was running the outboard above 3800 RPM. It starts reading-out 600+ depths and spotting fish that aren't there when I'm running in 10-20ft of water. At this point I'm kind pissed at myself for going with a Humminbird. I always take the unit off and store it indoors when it is not in use. After going through the Support part of their website I am thinking this may be an electrical grounding issue OR interference from the outboard. Any ideas?