[ESS] par(ask=TRUE) locking

[markleeds at verizon.net]

Hi: I'm a novice in ESS so I just use it at a very basic level but I really like it. Unfortunately,
when I run the code below, it locks up and I 
have to kill the process using ps -aux and I'm confident that it's due to the par(ask=TRUE).

is there anything i can put in that file 
.xemacs/init.el to make below work. I really don't use
par(ask=TRUE) much and I can always just use source
at an R-prompt if necessary so , if
it's more trouble fixing this than it's worth,
that's fine. i put the code in my init.el file
below the R code and I don't even remember what
the commands do ( they were all donated
by various people on the list when I had questions) 
but I know I need them to make ESS feel comfortable 
for me.  Thanks.

R code that causes locking
#==================================================

x <- data.frame(A=rnorm(100), B=rnorm(100), C=runif(100))
par(ask=TRUE)
sapply(names(x), function(.name) {
  hist(x[[.name]], main=.name)
})


init.el CODE
#==================================================

(load "/opt/mark/ess/ess-5.3.6/lisp/ess-site")
(eval-after-load "comint"
'(progn (setq comint-scroll-to-bottom-on-output'others)
(define-key comint-mode-map "\C-a"
'comint-bol-or-process-mark))
)

(defun my-ess-mode-hook ()
(local-set-key[up] 'comint-previous-input)
(local-set-key[down] 'comint-next-input))

(add-hook 'inferior-ess-mode-hook 'my-ess-mode-hook)

(put 'upcase-region 'disabled nil)

(put 'downcase-region 'disabled nil)