The 10,218,632 number includes redirects, if that helps. There must be more than 2.6 million pages by now, as just articles accounts for 2 million, so my guess is 5,654,236 is the number of non-redirect pages.
Oddly, with my (slightly-modified) mwdumper, I get the exact number of rows that I expect, with the latest enwiki input. It takes about 30 minutes to import the whole thing from a cold "drop if exists" on the relevant tables and import it.
Perhaps Matt is running out of some resource on his machine? MySQL limit? RAM limit? Something else?