Hey Alex, in the U.S. at least, a good trick for cementing Google's understanding of your client's locations is to manually add each place in Google MapMaker. EVEN IF IT'S THERE ALREADY. Just go through the process and try to add it, when it asks if it's a duplicate, accept that option. It'll then say it's discarding your changes, but click OK and then Save. Mike Blumenthal told me at lunch at SMX Advanced this year that he recommends doing that every couple of months even if there don't seem to be changes. If I remember correctly, he said Google trusts the MapMaker updates a LOT. Pretty sure David Mihm told me the same thing. And from my own client's little projects, I know that they're manually reviewing these, so that makes sense.
See if that helps...it'll just take you 5 minutes to do it, and then a week or two before they review your update.
Google's confidence in a business' current physical location seems to be pretty important to their algo (and it makes sense, as they look foolish anytime they direct a consumer to an empty office!).
MC