Hi Guys,
As some of you might already have noticed, MapQuest have changed the policies on their geolocation API, breaking our previous geolocation defaults. We briefly switched the default API to Open Street Maps, but due to the large Observium userbase they weren't able to support our request load, and we've since had to switch to Yahoo's geolocation API.
If you've kept the subscription version up to date, you should already have these new defaults. The community version can change the geolocation API in the config.php, but doesn't currently support the Yahoo API, which will come in the next release.
Details for settings can be found at : http://www.observium.org/docs/config_options/#syslocation-configuration
Observium also has support for Yandex and Google geolocation, and though Google's geolocation works best, it can only be used with a commercial license, so that can only be enabled by organisations with such a license.
This means that some addresses which previously geolocated may not geolocate properly now (each API has its own quirks when it comes to parsing addresses, so ones which worked before may not work now, and vice-versa!). We're investigating setting up our own geolocation and map imaging servers, along with switching to a new mapping library to try to remove reliance on external organisations.