Exactly. Why would she call Jeffrey Hopkin's parents on July 16th. We know she had already given this name to Lee and LE, telling them he introduced her to ZG.
As per the REAL Jeffrey, he said he went to high school with her and had not seen her is at least two years and he saw her at a restaurant once and said hello.
We know that on July 16th - she sent out text messages to all her friends notifying them to their utter shock that Caylee was missing.
My guess is that she didn't have Jeff's number and didn't know he did not live with his parents and to make her story credible she looked him up in the yellow pages or maybe had his old number saved somewhere and called their home to make it LOOK like she still had a relationship with him. Or it could have been CINDY or GEORGE calling to ask them NOT to speak to the press.