escape character bug?

[Katsunobu Imai <imai@sakura.bpe.osaka-u.ac.jp>]

I'm using MCL 2.0, and I have a trouble in using pathname escape 
characters.

(In the following message, character "\" in the pathname strings
means Macintosh escape character <option-d>.)

;; I want to create Macintosh file "fo\o"
? (setf f (pathname "quantum:fo\\o"))
#P"quantum:fo\\o"
? (create-file f)
#1P"Quantum:fo\\\\o"   <- escape character doubled, why?

Created Macintosh filename: "fo\\o" -> this shuold be "fo\o"

If I want to escape escape character, what shall I do?

-----------
Katsunobu Imai
imai@bpe.osaka-u.ac.jp