Problem with ispell in GNU Emacs

[fritz zaucker]

I just installed ispell on a Sun Sparc station and it works fine from
within Emacs.  When I run the same version of ispell from within Emacs
on my 386 under Interactive Unix (ver. 2.0.2), a SysV3.2, the ispell
process never returns to Emacs, except I kill it from another window.
It therefore think I have a problem with my Emacs.
The problem occurs in the following part of  ispell-word:
         (while (progn                ;; Wait until we have a complete line
                   (goto-char (point-max))
                   (/= (preceding-char) ?\n)
;;; HERE
)

If I place a call to the debugger   (debug)   at  HERE, the debugger get's called. Pressing  c  for continue in the backtrace window  continues execution and everything is fine!!!

Could anybody give me a glue what the problem could be?
I don't see any difference.

Thanks

Fritz