Google detected a 404 error to some of our product pages that are not errors.

Selected answers from the Dumb SEO Questions Facebook & G+ community.

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  Dave Elliott: I'd have a look at page speed or see if there is something that is preventing the page from fully loading or anything like that.
  
  Either that or i'd decide not to care because google is wrong and the page does exist.
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  Mark Steenbakkers: In your robots.txt you declare that /cache should not be indexed. This could be a problem if your SEF URLs are stored in the cache. ;
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  Kenneth Villegas: thanks Mark!
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  Luke Ciciliano: Did you test the page with Webmaster Tools' "fetch as Google" function +Kenneth Villegas? Also, look at the report and see how many times the site was unreachable. It may be a one time isolated incident and, in such cases, Google will tend to disregard the error. ;