Updated to v0.9.2 to improve the accuracy of the route planner when using the advanced cost optimization settings.
The original planner used the standard A* algorithm, but that turns out to be incapable of guaranteeing optimal routes when using more than one cost metric -- that is, it could minimize jumps, but would not always find the optimal route if there was a cost penalty for refueling stops, or if the cost for fuel use was more than a tiny fraction of the cost per jump.
The new planner implements NAMOA*, which is a more recent generalization of A* that can correctly optimize for multiple cost metrics simultaneously. With the "advanced" mode disabled you shouldn't notice any difference, but if you make use of the fuel or refuel cost optimization settings, your routes should now be guaranteed optimal.
But as always, the trade-off for accuracy is performance; searches are quite fast when they only have to optimize for jumps, and fairly fast when they only have to optimize for fuel. But combining cost settings can make it take considerably longer to find the optimal route, especially if the fuel cost is more than ~10% of the jump cost. It will eventually finish (and the dots will keep animating to let you know it hasn't locked up), but for very long routes in ships with very long jump ranges, it could take several minutes.