Player moving too fast

I have made a working ask fish farm. When I set it up to run (hold down use button and go away) after some time the server starts sending messages that the player (myself, the only whitelisted player) is moving to fast. I'm just standing still and haven't moved. After about 3 or 4 messages it boots me for a timeout. I have 2gigs ram allocated to the server and fly is allowed which seem to be common fixes.