A fair few visitors have complained about listed hacks (usually involving numbers like 1369, 1379 or 8888) not working on some players - i.e. you can access a hidden menu displaying a region code but you can't actually change it

After some research, I've published an article detailing the problem, listing the manufacturers who have actually bothered to do something about it (issuing a firmware upgrade which when completed means the code can be changed), and invited folks to post me details of players affected by the same problem. Hopefully, it will act as a useful reference point for people who want to contact manufacturers of players exhibiting the same fault.

The fault relates to one particular chipset, the MediaTek MT1379, which underwent a change in mid to late 2003, resulting in a new on screen display (OSD). It seems, unfortunately, that a whole batch of chips were affected by the glitch mentioned. It now seems that newer chips are fine again, so presumably MediaTek were to blame, rather than the manufacturers.

The article's
here
if you're interested - please spread the word on any websites you visit where you come across this situation.