Michael Isikoff has a piece in Newsweek’s Periscope (which you all remember from Koran flushing infamy) shedding more information on why Rove is going before Fitzgerald again:
But Rove did not disclose this conversation to the FBI when he was first interviewed by agents in the fall of 2003—nor did he mention it during his first grand jury appearance, says one of the lawyers familiar with Rove’s account. (He did not tell President George W. Bush about it either, assuring him that fall only that he was not part of any “scheme” to discredit Wilson by outing his wife, the lawyer says.) But after he testified, Luskin discovered an e-mail Rove had sent that same day—July 11—alerting deputy national-security adviser Stephen Hadley that he had just talked to Cooper, the lawyer says. In the e-mail, Rove said Cooper pushed him on whether the president was being hurt by the Niger controversy. “I didn’t take the bait,” Rove wrote Hadley, adding that he warned Cooper not to get “far out in front on this.” After reviewing the e-mail, Rove then returned to the grand jury last year and reported the Cooper conversation. He testified that the talk was initially about “welfare reform”—a topic mentioned in the e-mail—and that Cooper then changed the subject. Cooper has written that he doesn’t recall a discussion of welfare reform.
Your guess is as good as mine, and I will just let Tom Maguire do all the heavy lifting on this one.