I' ve been reading about DS lite for ages, but today I' ve encountered a large thread on Lik-Sang forum dedicated to D-Pad problems.

http://forum.lik-sang.com/showthread.php?t=14021

It seems that a lot of people have trouble with it being totally unresponsive in diagonal directions.

I got my black DS Lite on Friday. In the first few hours I noticed the problem. I took it back and got another one. This also had the same problem. By the time I took that one back the clerk started giving me dodgy looks. In the end I settled for the 3rd one which also has the problem. I' ve tried to ignore it but after a week my thumb is really sore and i' m starting to admit that it really does bother me. How do we go about complaining to Nintendo?

and another goes:

On the same day i bought a white DS Lite for my partner. In comparison the white one is alot more responsive in the diagonal directions. there is definatly something wrong with the black ones. I rang Nintendo europe this morning after my post and they said that there was prbably a dodgy batch

The thing is that most people say they have this problem on both white and black DS lite systems.It' s hard to say what explanation is good, but it really is confusing a bit.

Still that design...