Updated

A key source who was named to back up CBS News' claims about the authenticity of documents used in a report on President Bush's (search) Air National Guard service has recanted his support, saying the network got the information wrong.

Retired Major Gen. Bobby Hodges (search), a key source behind a "60 Minutes" story that claims Bush shirked his guard duty, said that now that he has seen the memos, he does not believe they are authentic. Hodges told FOX News that CBS did not call him until two days before the piece aired on the network last Wednesday night, and never offered to show him the memos. He said the network only wanted to discuss their content, not their authenticity.

CBS, however, is standing behind its report that Bush refused a direct order to take a required medical examination and discussed with the late Lt. Col. Jerry Killian (search) how he could skip drills in order to go work on a political campaign. The memos, which carry the signature of Killian, who was commander of Bush's Texas Air National Guard (search) fighter squadron, are disputed by Killian's son and wife, who said Killian did not keep records like the ones of which CBS had copies. Killian died in 1984. Bush served in the Texas Air National Guard from 1968 to 1973.

Bush Memos (pdf)

In addition, on Saturday, the Dallas Morning News reported that one of the officers who allegedly pushed to clean up Bush's record in August 1973 had, in fact, retired 18 months earlier, on March 1, 1972.

The "60 Minutes" report relied on a memo from Col. Walter "Buck" Staudt, former commander of the Texas Guard, which allegedly pressured another officer to "sugar coat" Bush's record. But the paper reports that Staudt was long gone by the time the memo was supposed to have been written.

CBS News responded to news reports questioning the documents in its Saturday evening broadcast, and issued a statement on its Web site.

"We believed General Hodges the first time we spoke with him. We believe the documents to be genuine. We stand by our story and will continue to report on it," the network states.

CBS has now spoken out twice since it came under fire this week that the documents used in its report are forgeries. In its Web report, the network listed several arguments about the authenticity of the papers.

Among the claims questioning the veracity of the documents is that the superscript that elevates the abbreviation after numbers — for instance a raised "th" in "111th" — was not available in 1972 when the documents were allegedly written. But, the network says, other military records released by the White House show superscript used as far back as 1968.

Another claim is that the New Times Roman typeface was not available back then. "But the owner of the company that distributes this typing style told CBS News that it has been available since 1931," the network reported.

The network also cites document expert Phillip Broussard, who had expressed suspicions about the documents, telling CBS News that he could not dismiss the documents as fake and would need to do more analysis before making a decision.

However, document examiner Sandra Ramsey Lines of Paradise Valley, Ariz., who examined the documents for the Associated Press, told the news agency that she was "virtually certain" the papers were generated by computer.

Lines said that meant she could testify in court beyond a reasonable doubt that her opinion was that the memos were written on a computer.

The White House has not contested the authenticity of the documents, but Bush aides have said the president's honorable discharge proves he fulfilled his duties for the Guard.

White House spokesman Scott McClellan added that the memos may have surfaced as part of "an orchestrated effort by Democrats and the Kerry campaign to tear down the president."

Nation editor David Corn said the dispute over whether the documents are true does not answer fundamental questions over Bush's service.

"The key facts that they talk to remain key facts: that is that Bush didn't give a good explanation about skipping out on his physical exam, that he says he was in Alabama. The records don't show that; he can't bring anyone forward to prove that he was there," Corn told FOX News.

Hodges said CBS anchor Dan Rather called him Friday night after the controversy hit, at which time he said he took Rather through the memos and explained why he believed they are not real. Hodges said the anchorman told him that document experts have confirmed their authenticity and would stand by the story.

Killian's former colleagues are also having trouble determing the authenticity of the papers.

Robert Strong, a former colleague of Killian's, said he's not a forensic expert and isn't vouching for the documents, but he didn't see anything about the memos that would make him think they were fakes.

"I didn't see anything that was inconsistent with how we did business," Strong said in an interview. "It looked like the sort of thing that Jerry Killian would have done or said. He was a very professional guy."

Retired Col. Maurice Udell, the unit's instructor pilot who helped train Bush, said Friday he thought the documents were fake.

"I completely am disgusted with this [report] I saw on '60 Minutes,'" Udell said. "That's not true. I was there. I knew Jerry Killian. I went to Vietnam with Jerry Killian in 1968."

The attacks and counter-attacks come less than two months before a presidential election in which past service by the candidates and the future of the nation's security have commingled. A Newsweek poll released this week shows Bush's lead over challenger John Kerry slipped in the past week from an 11 point advantage reported after the Republican convention to six points now with Bush at 49 percent and Kerry at 43.

John Avlon, author of "Independent Nation" and a columnist for the New York Sun, said even with this controversy seemingly favoring them, Democrats are missing opportunities to capitalize at every turn.

"Politics follows the laws of physics — for every action there is an equal and opposite reaction. But that's just the problem. With [vice presidential candidate John] Edwards and everything else, they are reacting and trying to get their game on a week after Labor Day," he said.

FOX News' Megyn Kendall and The Associated Press contributed to this report.