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Last month I heard a rumor that Google was going to do some kind of recalculation in the area of semantics - and this increased fuzziness could be part of that kind of effort.
At any rate, I've actually started to file a "complaint" when the results are particularly frustrating - by using that small link at the very bottom of the results page that says "Dissatisfied? Help us improve".
Im also having to use + "" more often and to be honest i cant be bothered. Ive had to dump Google and use bing three times this week to get results that are on target.
At this rate i will change my default search engine to bing, im using G out of habit and its no longer delivering in 30% of cases