you may want to recalibrate. I don't think I have that problem. In fact, I'm quite impressed with just how precise it seems to be. (I'm in the middle of an intersection.. it's in the middle of an intersection.) Occasionally it'll be off but it's so rare I barely notice.
anyway... if you don't want to reset the unit (like I've been doing when it freezes up on me) I've found a better solution to that... and seemingly your problem. (since resetting means you'd have to reprogram certain things.) basically... just hit 'modify current location' and select a place somewhat close to you. in a minute or so it'll correct itself and should recalibrate... if not, you may need to call pioneer and figure out what the problem is. ... or just get used to the lag.