Frontier had dozens of bugs...
The autopilot would crash from time to time if you tried to dock in a planet, but this only happens if you use the accelerated time. Do it in real time and this never happens.
If you buy a passenger cabin, get some passengers and then try to sell the ship, you will be told you can't sell it because it has passengers, but you STILL get the money for it.
If you try to bribe a cop and he doesn't accept its, your fine will be raised. Keep on trying to bribe the cop, and the bill will keep on raising, up until it gets back to something like 100 credits, so you can easily pay it.
There are planets that if you get too close of it, the gravity of it will pull your ship, and then you just WON'T be able to take off again, and you are stuck in the planet. (Well, that may be realistic and intentional, but it's pretty stupid)
If you get in the galaxy map, and choose a VERY VERY far system to go, you get an "on range" signal, and then you are able to fly to this system with just a 1t of fuel. I never found any use to this though, as those systems are pretty much useless.
On an ordinary A500, if you fired a laser docked in a planet, you would be attacked by the cops... but you are attacked by SO MANY Vipers that the game just drops to 1 frame at every 3 seconds, and it's just impossible to survive... (Ok, that's not exactly a bug, but it's also really stupid)
UNLESS... I don't remember exactly how to do it, but there was something about after being attacked by the vipers, you could land in a certain way, and instead of the vipers shooting at you, they would all crash in the ground (And all the explosions would make the frame rate even worse)
still a great game