(imported topic written by SystemAdmin)
It looks like Apple may have changed the 64 bit binary for iTunes 10.5.2. I get the following error when trying to update.
iTunes64Setup.exe Failed
Download error: “Error processing completed download: Requested SHA1 247e0910f9af8d1500bde249e6f0d48013c41d does not match actual SHA1 247e0910f9af8d1500bde249e6f0d48013c41dc2”