Alexander Nenashev (1997) and Alexander Graf (2001, 2004) are the same person.
but hadn't yet made the correction. The info is confirmed on Wikipedia, Alexander Graf:-
born Alexander Nenashev, 25 August 1962 in Tashkent, Uzbek Soviet Socialist Republic, USSR, is an Uzbekistani-German chess grandmaster. In 2000 he moved to Germany and took his father's name.
The other error was new to me.
Mohamed Esam Ahmed Nagib (FIDE WCh 1999) and Essam El Gindy (2004, 2007, 2009) are the same person.
This was confirmed on a page from the Polish version of Wikipedia, Essam El Gindy, translated by Google:
Essam El Gindy (born 14 July 1966 in Cairo) - Egyptian chess player, grandmaster since 2008, the end of 2000 known as Esam Mohamed Ahmed Nagib.
In both cases, it would be interesting to confirm that the FIDE ID handled the change correctly (see Structure of the FIDE ID for background). While I was working on these changes I was reminded that another sharp-eyed visitor had spotted an error on my index of World Chess Championship : Zonals page. For cycle 16, zone 4.2, I had noted that I was missing info on how the player Adly of Egypt had qualified for the next step in the cycle, the 1993 Biel Interzonal Tournament. This did not jive with Glenn Giffen's page, Zonals in the Americas and Africa, which listed Esam Aly Ahmed of Egypt as one of the qualifiers from Africa.
My first problem was that the 1993 Biel page had no mention of Adly, Esam Aly Ahmed, or any other player from Egypt. I located a printed crosstable from 1993 and discovered that Essam Ali A. of Egypt was qualified to participate, but forfeited the first round and was dropped from the tournament. My corresponding PGN file for 1993 Biel (last touched in August 1997, the month before I first released the WCC site!) confirmed this. I corrected both the 1993 Biel page and the index of zonals.
That first problem alerted me to a second problem, where the Arabic name had four valid transliterations -- Esam/Essam Aly/Ali -- all found using Google, although 'Esam Aly' is by far the most common variant. A browse through the various pages did not resolve the original question, how he qualified into the 1993 Interzonal. I did, however, discover that he was no longer with us. From The Sunday chess column (telegraph.co.uk) for 16 November 2003 by Nigel Short:-
After returning home to Egypt from last month’s African Games in Abuja, Nigeria, Esam Aly Ahmed, a 38-year-old International Master ranked sixth in his country, dropped dead from cerebral malaria. The 60-year-old head of delegation did likewise the following day. The disease, which requires urgent treatment, had not been detected in time.
These various researches left me little time to tackle any other item on my long TODO list, so I spent the available time delving further into the Complete History of the World Championship. An unfortunate side effect of these researches is to unearth elsewhere on the web many unattributed copies of the original material.
For example, a search on "there have been many matches between the leading players" returns not only the original page History of World Championship matches (forums.ubi.com, 11 July 2008), but also a bootlegged page World Chess Championship 1886 Pre-Fide (pakchess.org, 4 September 2009). I'm sure the forums.ubi.com page is the original, because I've also been copied by the pakchess.org site. For example, the page The History of Chess | PAKCHESS has links to copies of many articles from my own page on Chess History. Authorized? Of course not. Attributed? You must be kidding!