The most recent enwiki dump seems corrupt (CRC failure when bunzipping).
Another person (Nessus) has also noticed this, so it's not just me:
http://meta.wikimedia.org/wiki/Talk:Data_dumps#Broken_image_.28enwiki-20080…
Steps to reproduce:
lsb32@cmt:~/enwiki> md5sum enwiki-20080103-pages-meta-current.xml.bz2
9aa19d3a871071f4895431f19d674650 enwiki-20080103-pages-meta-current.xml.bz2
lsb32@cmt:~/enwiki> bzip2 -tvv
enwiki-20080103-pages-meta-current.xml.bz2 &> bunzip.log
lsb32@cmt:~/enwiki> tail bunzip.log
[3490: huff+mtf rt+rld]
[3491: huff+mtf rt+rld]
[3492: huff+mtf rt+rld]
[3493: huff+mtf rt+rld]
[3494: huff+mtf rt+rld]
[3495: huff+mtf data integrity (CRC) error in data
You can use the `bzip2recover' program to attempt to recover
data from undamaged sections of corrupted files.
lsb32@cmt:~/enwiki> bzip2 -V
bzip2, a block-sorting file compressor. Version 1.0.3, 15-Feb-2005.
Copyright (C) 1996-2005 by Julian Seward.
This program is free software; you can redistribute it and/or modify
it under the terms set out in the LICENSE file, which is included
in the bzip2-1.0 source distribution.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
LICENSE file for more details.
bzip2: I won't write compressed data to a terminal.
bzip2: For help, type: `bzip2 --help'.
lsb32@cmt:~/enwiki>