To fix a "possibly problematic" Mappable Target, you first need to know the target's actual location. If you know the location, you can fix the target with the Pin Drop Locator. To fix the target location, follow these steps:

  1. Find the problem target on the My Targets page. To do this, click Setup -> Targets and select Show only possibly problematic Mappable (or enter the target name or ID in the "Search text" box). Locate the problem target in the list: 

  2. Correct the Map Search Info (if necessary). Make sure that the Map Search Info is correct -- a misspelled street name is enough to throw Google off! If you make any changes, click the Map & Save button. Got three stars now? You're good to go! If not (and you know the actual location) go on to Step 3. 
  3. Fix the location with the Pin Drop Locator. To do this, click on the map link on the right. This brings up the map popup, showing a map pin where Google Maps thinks the address is. To relocate it, simply drag and drop the map pin on the desired location, then click Set New Location

Once you've dropped the map pin, the target entry is updated with an M (to indicate that the coordinates were manually set). This does not change the accuracy rating (you'll still see two stars, in this example), but it does remove the target from the "possibly problematic" list.