Kerbal Space Program

I posted about this in Technical Support October 28 last year. http://forum.kerbalspaceprogram.com/index.php?/topic/151030-docking-summersaults/#comment-2827866
In November I reported a game breaking bug http://bugs.kerbalspaceprogram.com/issues/13314 which has also been pretty much ignored.
Good Luck! :)

I tested this by placing different types of docking ports, command pods, and probe cores around a cylindrical test vehicle. If my root part was in the central stack then only the docking ports at either end of the stack held the target properly when at close approach for docking. Any docking ports or control points that were offset from the central stack or aimed radially outwards do not track properly.

HOWEVER! If you use the re-root tool to make a radially mounted docking port the root port then that docking port DOES track the target correctly. Further testing shows that when SAS is tracking a target it will align your navball to face in the direction of whichever control point you've selected BUT it will use the base of the root part of the craft to determine "center" for tracking purposes and calculates the angle from the target to the base of the root part - instead of the angle from the target to the selected control point. This means that if you are using a large ship and its root part is placed at some lateral distance from the docking port you are controlling from then the SAS will keep turning your ship to bring the base of its root part in line with the target - which causes the docking port you are trying to use to continue to point away from the targeted docking port.

For SAS "hold target" the angle from the targeted docking port is being calculated to the base of the root part of the ship being controlled rather than calculating the angle to the selected control point. This isn't very noticeable at large distances, but when at close range it makes it impossible to use SAS "hold target" to dock large ships with an off-center docking port.