Spacecraft Range bug

There apairs to be some maximum range a shipdesign can travel. in beta2a, I played on a huge map and I use several survey ships to systematicly search for anomalies. Everytime I reach the border of the maximum range of the ship, I upgrade the survey ship to a more advanced model with longer range and higher speed. This worked fine until the last time. Instead if increasing the range of my ship, the range barrier became square instead of a circle. Since my ship was already on one of the 4 axes my ship range did not increase.