AWE798 & AWE798P Why two flights?

Tonight 22 Oct 2012 there are two data blocks showing for AWE798 and AWE798P, KPHL-EHAM. They show the same acft, alt, and spd, one immediately in trail of the other. Is this a data anomaly or an estimate of some kind?

I’d guess 798P is an anomally as it is showing up as ‘estimated’ near Bangor.