Um, yes, the first results may come from OneBox, which is not from their "Algorithmic" search, but from a separate service that triggers on certain keywords, like "music", "movie"... and "csco". Adding commas just makes it not trigger the OneBox search. It used to be that the OneBox results are more visually different from the rest of the results, but the recent redesigns makes them very much alike.
OneBox is also used to implement features like "10 km in miles". See also http://searchengineland.com/meet-the-google-onebox-plus-box-direct-answers-the-10-pack-26706 I'm not use if they still use the word "OneBox" to describe this feature though, but it is still used in the Google Search Appliances.
Disclaimer. IANAGoogler, reposting this from my reddit reply.