I'm currently using Google Maps 4.5.2. Provider is Entel in Santiago, Chile.

Most of the time the GPS works fine. Anytime I am away from home, it is exactly correct (walking, bus, taxi, etc).

The problem is when I a home. About 6 weeks ago I moved to a new location in Santiago. According to Google, the distance between my old location and the new on is 1.7 km.

My strange problem is that when I return home, it always shows my location as the old apartment. I makes no sense, as when I am a block away, it shows the correct location. As soon as I enter my apartment, the location jumps back to the old apartment.

Anyone have an idea as to what might be causing this?

I can think of two possabilities:
1) You can't get a good GPS signal in your apartment and it is using cell site location;
2) You have a Wi-Fi router that Google vans located to your old apartment and they haven't been by to re-located your router.

Using a cell site location seems not to be the problem, as UberSoc uses that and the accuracy is pretty good.

It does seem to be related to the router, since it does correct itself when I disconnect the wifi (when it can get a satellite fix). So assuming Google has locked the old address associated with the router into their system, is there anything I can do to correct the problem?

I'm a little confused as everything I have read says Google has stopped collecting this data, and also that they did not collect it on secured routers. The router was brought from the US a year ago when I moved here, and the WEP info was created there, so it has always been secured here in Chile.

You have missunderstood the "collection" of data issue. The software Google used to get the information about Wi-Fi routers to geolocate them had the option of collecting data from open access points. Google mis-configured their software to enable this option by mistake. They have since corrected that, but as far as I know they still collect the identity informtation available in the clear (even for secure access points) to feed their geolocation database.