Docking autopilot is not working 100%.

Quite often it happens that it lines ships or ship and station perfectly and going for docking but when it is 5-3m or even closer to docking port it shut down autopilot saying "..moving to dock at 0.00 m/s". So the ship drifts away. :( I cannot really perform that final stage of those 5m or less metres because in those moments I have about 2-5 FPS as my orbital station is kinda big.