I had Error 67 too when i got mine. Ended up scrapping the HDD that came with it, used a brand new one purchased from DVDBoxoffice. No error whatsoever since. Done some "surgery" on the fcuked-up HDD as well, you dont want to see what happened to it.

Had to remove the HDD and used a Memory Unit to load my profile in, then it works. The HDD had been in a landfill somewhere since. At least you guys are lucky to have referencing material and anecdotal reports from other owners now, at that time i had this problem, there is nothing to refer to other than what few lines of sentences MS have in their Xbox FAQ.

US Xbox 360, at that time, no such things as "return back to <insert shop here> to claim warranty" or "go to Singapore and fill in details for 1-to-1 exchange". My Xbox 360 is the Zero Hour Xbox 360, meaning it comes from that Microsoft Mojave desert launch event. This alone would have scared non-early adopters, with the usual "first batch is buggy and problematic" line of thoughts, but i see more "younger" batches than mine dropping like flies.