i dont have problems with harbors missing but the docks arent rendered until your "much" closer then the ships and harbors so your unobstructed very long range shot at a docked ship has a pier or dock appear in its way like magic to catch your torpedo and you've wasted it.
this situation hasnt changed even thou i went from win xp with 2gb ram to my vista + 4gb ram upgrade. all i got was prettier views
i think sober is right about what some people mean by problems with the harbor rendering issue, its just there are other rendering issues that are game related too.
ships are rendered and can be seen at the greatest distance, then land formations, then harbors, and the last to be rendered and at what i feel is too short a distance will the dock/pier finally show up.