Can you spell “SEC investigation?”  There is definitely going to be one after this.  A post at CNN’s new social news site, iReport, resulted in Apple stock plummeting this morning, when it was rumored that Steve Jobs had suffered a heart attack.  iReport allows users to post unvetted stories, which then — after vetting, may be posted to the iReport page on CNN.com.  This story obviously didn’t make it there, and has since been taken down.Interestingly, this user has never submitted a story