Bruce, it is in a semi up position as a sort of collision protection system, it pops up if it hits anything, but can also pop up after a big jump at 30-40kts. You can remedee this by tightening up the nut & bolt either side of the rubber washers. The position of yours does look to be slightly higher up the transom than mine which might just be the cause.
Also you could try increasing the ping speed from the default 50% to 100% on the sonar. If you do this you may get a second bottom echo cluttering the screen which can be eliminated by decreasing the sensitivity slightly.
If In Doubt, Go Flat Out!!