In Washington this spring, CNN/U.S. president Jon Klein greeted FNC anchor Greta Van Susteren, a former CNNer, at a couple of parties. “I would have never let you go,” Klein whispered.

Watching her reports from Aruba last week, it’s obvious why. She scooped her former net all week and recorded her best ratings of 2005, with over 2.8 million viewers on Thursday night. “She thought it was a good story because it is a whodunit,” a source close to Greta tells TVNewser, but “I don’t think anybody expected that it would be this big.”

In the ratings game, Greta beat Bill O’Reilly on Wednesday and Thursday night. Is the “humble correspondent” feeling a little humble that On The Record has topped the Factor? That’s unlikely, the insider said: “There isnt that inter-show competititon like there was at CNN. It’s much more of a team thing at Fox.” The only question is: Will Greta’s new viewers stay tuned once she returns from Aruba? After taking the weekend off, she’s back on the island for tonight’s On The Record…

> Update: 3:40pm: “O’Reilly may have been a ‘factor’ in the stellar ratings that Greta amassed last week,” an e-mailer says. “He had her appear on his program a few times last week to give updates on the Natalee Holloway story, and commended her reportage each time. And he further told everyone to be sure to tune in to ‘On the Record’ later, as Greta would have even more updates.”