Big problem. The weapon-fire should be stopped completely, but instead it simply doesn't interact with the station. Allowing astronauts and undocked entities to be damaged and destroyed even when behind the stations shielding.
Couple this with the fact that some weapons appear to have longer actual ranges than published (so that hostiles can shoot you from distances that prevent them from appearing on the HUD), this seriously nerfs the actual usefullness of faction homing a station or planet.