The wisps have never been very good in EQ2. Sometimes they give you a pointer in the right direction, but in tight quarters they also have a chance to be pointing the wrong way or taking a shortcut (Hooray wisp going through the wall that you can't
).
And yeah. Supposedly wisps aren't supposed to show unless you're a certain distance from the target or less. The problem? They often disappear entirely when they recalculate as you move (and does that recalculation annoy anyone else as much as it does me? Can't it just calculate it right the first time, or at least not so blatantly change it's mind?) or they sometimes show up when you're relatively far away and then disappear until you get close (if they come back at all).
They were implemented pretty decently in EQ1, but the wisps definitely drop the ball in EQ2.