In brushing up on my copyediting skills, I've reread Strunk and White (and yes, laughed out loud several times. Really -- it's a very entertaining read! Check it out!) and in so doing, discovered that gerunds really DO take a possessive pronoun. (e.g., I was really irritated by her finishing the tequila...) For some reason, this construction has always struck me as lowborn and foul.
OK, so I still think it's a lousy way to speak/write, and To Be Avoided (S&W also asserts that sarcastic capitalization is outdated and stupid, but so what). But I will no longer look down my WASPish nose at those who choose to use said construction. Because that would make me snobbish, and wrong. And I hate being wrong.