There are two different places that the counts are incremented, and occasionally (once every 2 weeks or so) a server glitch causes the most recent views to not get committed to the database. This means that when the site gets restarted, a few views can be lost, but it is rarely more than 10 views in the worst case. Likewise, the bug can occur in reverse so you might see a jump forwards when it re-synchronises itself.
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