Jenna Jameson’s doing better acting now than in her entire adult industry career.

from www.tmz.com Jenna Jameson has told two completely different — and contradicting — stories about the incident that led to the arrest of her baby daddy Tito Ortiz yesterday … and they’re both caught on tape.

When we first saw Jenna last night — around 8 PM — she adamantly stated that Tito did not lay a hand on her.

But a few hours later — around 10 PM — the story had changed … and Jenna repeatedly referred to Tito as a “wife beater.”

So what happened in the time span between her stories? Well, one minor thing — around 9:30 PM — Tito held a press conference in which the fighter claims he never touched her … and insinuated that Jenna’s injuries were the result of her alleged addiction to OxyContin.

So now the question is …

The Tito didn’t beat me tape:
www.tmz.com/videos?autoplay=true&mediaKey=bec8609a-084b-4763-b1d6-197f38c5328a

The Tito’s a wife beater version:
www.tmz.com/videos?autoplay=true&mediaKey=1e9d8c73-c448-459e-aa69-5686b3e37cca

An earlier posting: Jenna Jameson claims Tito Ortiz got very violent — throwing and injuring her — and that he’s falsely accusing her of Oxycontin addiction because he’s “very, very desperate.”

TMZ just spoke with Jenna — while she was driving to Las Vegas — and her version of what led to Tito’s domestic violence arrest is brutal.

Jenna claims that during an argument Monday morning she, “said something very hurtful to his ego.” She alleges that Tito then grabbed her and, “threw me into the bathtub and tore two ligaments in my shoulder.”

Tito’s attorney Chip Matthews strongly denies that, saying … “He did not put his hands on her, he did not hit her, he did not do anything to her.”

Matthews claims Tito found pills in Jenna’s pants pocket — and that when Tito confronted her she had an “emotional meltdown.”

Jenna says Tito’s addiction allegation is, “completely false” and “the last nail in the coffin” for their relationship.

Stay tuned…