Newcard: a curious bug!?

[Dom]

I have a single card stack.

I don't want the user adds a new card; so I trap the "newcard" message
(accordingly with the help)

If I write:

on newcard
  send "delete this card" to this card in 1 sec
end newcard

That works...
But if I add a warning, such as in:

on newcard
  answer "Only one card, please!"
  send "delete this card" to this card in 1 sec
end newcard

That doesn't work... the newly created card is not deleted!
If I go further and add again new card, it ends with a blank dialog and
Rev freezes...

--