ispell-buffer skips repetitive suspects after the first is accepted

[Jürgen Hartmann]

If a suspicious word is accepted once by pressing <SPC> in an interactive
ispell-buffer session, all further occurrences of the same word on the same
line are skipped.

Here is an example:

Open an Emacs 24.5 session (it is the same with Emacs 24.4) by

   LC_ALL=C emacs -Q

and enter the following line in the *scratch* buffer:

   The term charset is short for charset.

Assume that the last word is a typo that should read "character set". Now
change the dictionary to american and run ispell-buffer. The first occurrence
of "charset" gets highlighted, but since it is correct here, we use <SPC> to
accept it once an proceed. But oops... the spell-check finishes immediately
without giving us the chance to correct the second occurrence of "charset" in
that line.

Is this a bug or a difficult to understand feature.
(I don't think that I like it.)

Does anyone has an idea how to bring ispell-buffer to offer all suspicious
words for correction?

Thank you for any advice.

Juergen