Different behaviour between M-x replace-regexp in function and in echo window

[luca . spinacci]

If I use M-x replace-regexp followed by
"\(//\)[[:space:]] *" <RET> "\1 " <RET>
the behaviour is correct - replacing any space
between '//' ed comment text
Ex.
//___Text... => //_Text...
where '_' is a space

If I use the same
replace-regexp "\(//\)[[:space:]] *" "\1 "
in a function no replacing is done - Replaced 0 occurences -

(defun comment-formatting(start end)
 (interactive "*r")
  (save-excursion
    (save-restriction
      (narrow-to-region start end)
      (goto-char start)
      (replace-regexp "\(//\)[[:space:]] *" "\1 "))))

So M-x comment-formatting has differnt behaviour. Why?


Thanks in advance,
Luca.