Had a discussion with Google Places management on Monday regarding the increasing problem of missing Google+ Local reviews and/or reviews that post but don't show up online on the live listing.
IMHO there is a combination of buginess/upgrade issues as well as some spam algos that may be wound too tight.
I'm under NDA with Google, but they gave us permission to share the following high level points.
See it on Scoop.it, via Google Places Optimization & Local SEO News
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