using open-i/o-file function

[Nicholas Papadonis]

I'm using MIT Scheme 10.1.5 and am curious why the following code using
open-i/o-file is not working as I expected. Does anyone know what the issue
is?

(define l "~/tmp0")
(define x ''(a b (c d) e f))

(let ((p (open-i/o-file l)))
  (begin (write x p)
     (flush-output p)
     (let ((r (read p)))
       (close-port p)
       r)));Value: #!eof

when I was expecting:

;Value: (quote (a b (c d) e f))

When using open-input-file or open-output-file the results are expected:

(let ((p (open-output-file l)))

  (write x p)

  (close-port p))

(let ((p (open-input-file l)))
  (let ((r (read p)))
    (close-port p)
    r));Value: (quote (a b (c d) e f))