Another old bug in Debian's BTS.  While the report is not too informing,
I wonder why M-delete is not bound to kill-word:

,---- C-h k M-delete
| M-DEL (translated from <M-delete>) runs the command
| backward-kill-word, which is an interactive compiled Lisp function in
| `simple.el'.
| 
| It is bound to <C-backspace>, M-DEL.
`----

,---- C-h w kill-word
| kill-word is on <C-delete>, M-d
`----

Would it not be consistent to bind M-delete to kill-word?