I'm still having issues with this as well. Sometimes it never updates at all; could be when leaving or when arriving, totally random. Sometimes it updates 15 minutes after arriving home, in which case either my wife or myself has been connected to wifi from the moment we hit the driveway.
EDIT: I should add that sometimes my phone gives me that iViri "Switch OK" message 3-4 times in a row. Aside from being annoying, it would also seem to indicate a bug of some sort.