Sometimes bright lighting can make cichlids shy or nervous. I've had fish act like that but after changing to softer bulbs, the behavior changed. Too much empty space can cause the same behavior. Introducing a few pieces of driftwood, pots, or some other structures will provide the fish with multiple places of cover, making them more secure to stay out. Dithers also help. I also agree with Ryan regarding the height of the tank. If the tank is positioned too low, casting shadows could frighten the fish.