The story...

There are inconsistencies in the numbers of passengers listed for Flight 77, leading some to believe that there were no hijackers at all. As Thomas R. Olmsted puts it:

"This is the list provided by American of the 56 passengers...

The AFIP suggest these numbers; 189 killed, 125 worked at the Pentagon and 64 were “passengers” on the plane. The AA list only had 56 and the list just obtained has 58. They did not explain how they were able to tell “victims” bodies from “hijacker” bodies. In fact, from the beginning NO explanation has been given for the extra five suggested in news reports except that the FBI showed us the pictures to make up the difference, and that makes it so".
http://www.sierratimes.com/03/07/02/article_tro.htm

Our take...

Problem #1 for this story is that Olmsted wants us to believe his first list (www.cnn.com/SPECIALS/2001/trade.center/victims/AA77.victims.html) is an official and complete passenger manifest from American Airlines/. In reality it's just a CNN page, though, and all they say is that "The Associated Press contributed to this report".

Switch back to the main CNN victims page instead, and we find this.

While the official number of those missing and dead will inevitably rise over the next few weeks, authorities from American Airlines, United Airlines, the Department of Defense, the New York City Medical Examiners Office and the New York City Fire Department, have released partial lists. They are linked below.
www.cnn.com/SPECIALS/2001/trade.center/victims/main.html

Partial lists? No surprise if there are missing names, then. Visit the main Memorial page (www.cnn.com/SPECIALS/2001/memorial), click "About this site" and you'll find further qualifications on the data.

This memorial lists those who died in New York City, Washington, D.C. and Pennsylvania when terrorists hijacked four U.S. planes on September 11, 2001. The list includes those listed as "confirmed dead" and "reported dead" by the Associated Press which defines the terms as follows:

CONFIRMED DEAD Includes victims who have been confirmed dead by a coroner's office or the Defense Department. It also includes those a court has declared legally dead, even if no body has been recovered. Once the court has made such a finding, a death certificate can be issued.

REPORTED DEAD Includes those whose deaths have been reported by family, employers, mortuaries, places of worship or by the airlines that listed them as aboard one of the four flights. Includes people for whom memorial services have been held, even if their bodies have not been recovered or positively identified. (Those identified by federal authorities as the hijackers are not included).
http://www.cnn.com/SPECIALS/2001/memorial (About This Site)

So the CNN report represented a dynamic document that was being updated as information was provided. Nothing overly mysterious about that. Note also that the hijackers are specifically omitted.

Still, now that Olmsted is pretending the CNN list is a manifest, he can point to “anomalies” and claim they mean something:

No Arabs wound up on the morgue slab; however, three ADDITIONAL people not listed by American Airline sneaked in. I have seen no explanation for these extras. I did give American the opportunity to “revise” their original list, but they have not responded. The new names are: Robert Ploger, Zandra Ploger, and Sandra Teague.
http://www.sierratimes.com/03/07/02/article_tro.htm

His list doesn’t prove “no Arabs wound up on the morgue slab”, only that they were not identified. And the list did not come from American Airlines, as CNN tell us: it’s a partial list compiled from media reports.

There’s still the little mathematical problem in the initial claim, of course. The CNN list contains 56 victims. His "autopsy list" obtained under the Freedom of Information Act has 58 names. Add the five hijackers onto the list and we still have only 63 names, yet supposedly there were 64 people on board. So who's the missing person?

Actually it's no secret at all, and even Olmsted tells us at the end of the article.

"The AFIP claims that the only “passenger” body that they were not able to identify is the toddler, Dana Falkenberg, whose parents and young sister are on the list of those identified".
http://www.sierratimes.com/03/07/02/article_tro.htm

So add Dana Falkenberg to the 58 identified bodies and we have 59. The remaining five? 

Nawaq Alhamzi
Salem Alhamzi
Hani Hanjour
Khalid Al-Midhar
Majed Moqed

Yes, add the alleged terrorists and everything matches up just fine. There are no "missing Arabs" at all.