Took me 2 weeks of being totally ignored and over 20 emails before I finally received this response...

Hello xxxxxxxxxxxxxxxx,

Thank you for your email. The last official audit on
the RNG was in 2003 although thousands of players
continue to audit it on a regular basis utilizing hand
histories and analysis programs. Please understand
that further audits on a random number generator are
not necessarily unless evidence arises that it has
somehow stopped performing as expected; such evidence
has not surfaced in regards to our RNG.

I hope that helps answer your question. Please let us
know if there is anything else we can do for you.

Regards,

Larry
PokerStars Support Team