party rigging in S+G's

[samatron]

I've long been an advocate of ignoring people who say a site is rigged.
However, I have been running a spreadsheet of my bankroll for about two years now. While the trend line for my pokerstars account is a very smooth line (the occasional bad period counterbalanced by a good period), the Party trend is excessively weird. The trend basically says when I am playing regularly, I am losing a lot (and to outrageous draws according to my notes!), yet when I cool it and play say a couple games a week, I get ridiculously improbable winning sprees. The variations seem to be too huge for a standard deviation.
It's like when I don't play much, Party wants to encourage me to play by giving me great cards. One S+G I played the other day, I got the following cards across the first five levels:
KK AK AA KK AA
That's across about 50 hands. Statistically, KK/AA comes up about 1 in a hundred hands. Highly improbably that I holed them four times in one game!
I don't want to ask it, but is party rigged to encourage infrequent players and take advantage of frequent players?