Today I see a second spike in my combined world position stats

[url=http://www.boincstats.com/stats/boinc_user_graph.php?pr=bo&id=252ea3e8b7dfa4d86bdac2bcc8d3fed9' target='_blank]http://www.boincstats.com/stats/boinc_user...bdac2bcc8d3fed9[/url]

I also see this coming back in other user stats (the positions above mine
in the combined user stats)

Is this a bug in one of the calculations ?