Bug in mref ?

Here's a transcript of a little exchange I just had with matlisp in
CMUCL. 

(The matlisp was checked out from CVS within the last couple of
hours).

Jacek.

----------------------------------------------------------------------

* (setq the-matrix (make-real-matrix '((1 2 3) (4 5 6))))
#<REAL-MATRIX  2 x 3
    1.0000      2.0000      3.0000     
    4.0000      5.0000      6.0000     >
* (matrix-ref the-matrix 1 1)
5.0d0
* (help mref)

In package MATLISP, the function MREF
=====================================
Same as MATRIX-REF
* (mref the-matrix 1 1)

Invalid number of arguments: 3

Restarts:
  0: [ABORT] Return to Top-Level.

Debug  (type H for help)

(MREF 3
      #<REAL-MATRIX  2 x 3
    1.0000      2.0000      3.0000     
    4.0000      5.0000      6.0000     >
      1)[:EXTERNAL]
Source: 
; File: /usr/local/src/matlisp-cvs/src/compat.lisp
(DEFUN MREF (I &OPTIONAL J)
  "Same as MATRIX-REF"
  (IF J (MATRIX-REF M I J) (MATRIX-REF M I)))
0] (defun mref (m i &optional j)
      (if j (matrix-ref m i j) 
     (matrix-ref m i)))
Converted MREF.
MREF
0] 0
* (mref the-matrix 1 1)
5.0d0