Sorry to say, I've had the same problem with the CD version of SP2--every attempt to extract the files ends with "Extraction failed--file is corrupt." This occurs whether extracting from the CD or from copied files on the hard drive; whether using a command line or the 'xpsp2.cmd' that comes with the CD.
If it's of any help, the last file being worked on was i386\root\cmpnents\tabletpc\i386\ptc_oobe.dl_.
Is there some way of extracting this stuff without the corruption check--especially if it's just this one file, and my having no interests in Tablet PCs! Am just trying to use it to develop a slip-streamed version of XP (Home).