I think it's just Google saying, "Aaa... what the hell do those Firefox users know about PageRank, anyway? No one will notice..."
Yes, everyone knows that only computer noobs who can't use Microsoft Word uses Firefox The average Firefox user closes yet another text document without saving again.
So I go and check out the Google Datacenter QuickCheck, bearing in mind some posts about pagerank jumping, and I see 216.239.53.99 and several others with pre-jagger PR, 64.233.171.99, 64.233.171.104, 64.233.171.105, 64.233.171.147, 64.233.185.104. These five are also showing pre-jagger backlinks! And then this from earlier in the evening: http://forums.digitalpoint.com/showpost.php?p=448971&postcount=31 WTF???? Edit: 216.239.53.99 now showing the newer pagerank, 64.233.179.104 also showing old PR and pre-jagger backlinks...