I've had both GPS units do sort of the same thing. When I enter 509 Dukes Road -- the units will have me go about a half-mile up the road from the house (our addy is 509 Dukes). So I looked around and found a button that let me set "this location" as home. Click while in the driveway -- no more mistakes. Funny, though, how the machines both had us out in the woods near home. . .
New query: How do I change the pre-set speed that's used to figure driving time to destination? I don't think the unit is learning from our driving -- seems to think we average 62 or so, and that's quite a bit above our true average. I'd like to get the correct number in there so I'd get more accurate estimates. The unit is the Garmin Nuvi.