I've always had probs with my diagonals but since I started pulling the pad out a little to help, it's definately gotten worse and it's more floppy too. That can probably be put down to the fact that I've given my little GP an absolute caning since the day I got it.....
Question about this grinding method; do you have to move the stick a long way to reach the point to move diagonally? I get the feeling it won't be very sensitive if you do this, I think I'd rather use little but accurate movements somehow