Word on the sidewalk is that Def Jam CEO Antonio “L.A.” Reid is on the verge of losing his job at Island/Def Jam and canceled an appearance at the Billboard 2010 Music & Money Symposium, claiming his son was sick in the hospital with a head injury and needed emergency surgery.

Hundreds of top music industry suits paid up to $1,000 each to hear Reid speak at the Billboard 2010 Music & Money Symposium at the St. Regis last week. But hours before the talk, delegates were told that his son was in the hospital with a head injury and needed surgery. Reid has four sons, from 6 to 29 years old, as well as a daughter, 8.

However, sources contradict that story about his son being in the hospital, saying that it is false and Reid didn’t want to speak at the Billboard event because he didn’t want to face inquiries about his uncertain post at Def Jam. Apparently, the folks at the label were very disappointed in the sales figures for Rihanna and Mariah Carey’s latest albums & want him out.

“There was speculation among other music executives that this was not entirely the truth. Reid didn’t want to answer questions about his future with Island Def Jam,” a source said. “The move left organizers panicked with no speaker with just hours to go. Vevo CEO Rio Caraeff agreed to stand in.”

One of Reid’s friends reached out to the NY Post and told them that he had to cancel because he was called away on family business; not because his son was ill. They also added that he “isn’t going anywhere” and plans to sign Jennifer Lopez  soon…

That was just a story that went around. He isn’t afraid to answer questions about his future with the label. He is about to sign J.Lo [Jennifer Lopez] and isn’t going anywhere.” A rep for Island Def Jam said, “It was unfortunate, but he was called out of town on personal business and hopes to be able to participate in a future symposium.” Billboard declined to comment.