Questgivers on the map
 

I was wondering, how do questgivers shown on the map actually work? Does it just display all the quests or just ones that I haven't completed?

Also, a lot of times it says there is a quest at an NPC who doesn't have a quest. I know it's probably because I have to unlock it through a chain or something, but is there any way to fix this? If not, it should only show up when you can get the quest, not always.. or at least say what you need to do to be able to get the quest.

Sorry if this post has poor grammar. I'm really tired.

Er.. Bump? :/

All Quest Givers are shown unless filtered by the lower levels to show Priorities menu setting or all quests from that source are flagged in the Carbonite Quest History as completed. Addons cannot get the real quest completion info for a character and we also do not know about prerequisites for a quest or if you have done those.