unexpected Del behaviour after C-d binding

[Dani Barral]

Hi,

I'm trying to configure the keyboard of my laptop into something more 
confortable for my hands. First I want to rebind some emacs commands and 
after I'll exchange some control,alt,... keys in X.

The problem I having with GNU Emacs 21.2.1 is that the behaviour of the 
Del key changes after this:

(global-unset-key "\C-d")
(global-set-key "\C-d" 'next-line)

Now everytime I press Del next-line is executed. However C-h Del returns:
<delete> runs the command "^D"
   which is a keyboard macro.

Could anybody what's wrong with those two bindings above?

Cheers

Dani