I posted this elsewhere, but seeing as how this is the main thread on the matter I wanted to throw it in.
1. Under Bush, the PDB has become shorter, a seven-to-10-page document containing "more targeted hard intelligence" items, with few longer than a page, according to a former senior intelligence official who was involved in the process.-
sourceThis contradicts the German article's claim that the PDB is usually only a page or two.
So according to the WP, Bush's PDBs are usually 7-10 pages (give or take, this one being 11 is not outlandish) and they contain individual intelligence items that are normally 1-2 pages.
Given that, it's certainly possible and, I think, likely, that the Bin Laden warning was simply one of the shorter "items" within the PDB. The other pages probably dealt with other issues not relevant to 9/11 or terrorism/Bin Laden in general. Given that the PDB is often characterized as a "world headlines" sort of thing, this would make sense.
2. There is a logic to the transition from the first released page to the second one. "We haven't been able to corroborate claims of Bin Laden's plan to hijack planes
BUT (turn page) the FBI is reporting activity consistent with hijacking planes."
I don't think there are missing pages
between the two that were released. They probably come before and/or after and, by point 1, are probably not relevant.
Edited because I assume people prefer working links...