We have two threads at the Google Places Help forums complaining about two different issues.

Missing Reviews:
The first is a complaint about reviews missing. As Mike covered this is a known issue. In fact, some of it was intentional and not a bug. Googler Stephan S. said yesterday:

As you can see, some of the reviews were removed algorithmically because Google may have found them to be low quality. Google did say that it may have impacted legitimate reviews, but overall they are happy with the changes and I am not sure if Google will change things.

Forum discussion at Google Places Help.

Duplicate Listings:

Linda Buquet, a Google Places enthusiast, posted a thread at the Google Places Help forum complaining about duplicate listings. Linda said she is seeing ‘minor duplication’ for businesses in the past day or two. She explained them as ‘minor’ because they are “a dupe with the exact same name, categories, description, images.”

In short, it seems like in some cases Google is showing duplicate listings. I personally couldn’t replicate this but Linda is pretty on top of these things.

Forum discussion at Google Places Help.