Model and TV presenter Kelly served less than a week on the panel of the talent show before she was axed in 2009 - and has admitted that she doesn't know why she was sacked.
Being interviewed by Keith Lemon for FHM, she said: "I don't know! I still don't know.
"I saw Simon Cowell once afterwards. I caught his eye and I thought, 'I'm not going to say hello to him, I can't be bothered', and then he kind of just sulked over and sat next to me.
"Then all of the photographers came and then they took a picture as if we were friends. We're not friends. I didn't know him before and I'll probably never meet him again.
"I don't understand why he sat next to me for a photo opportunity. I don't know. It was weird."
And she sounded frustrated by the whole experience as she continued: "They're all weird. I've been in the business for 15 years. I turn up and I do my job. I'm professional and if I'm not comfortable, I'm honest, I'm really straightforward.
"If it was editing, if it was bad, they could have edited it to make me look good... They said 'be yourself', and I was, and then they fired me!"