slime + chokes on temporary-file-directory set to "~/temp" on Windows

I am running Windows versions Emacs and CLISP.

If I have temporary-file-directory set to "~/temp", slime loading will report ;; Loaded file C:\Users\977315\documents.slime\fasl\2013-09-29\clisp-2.49-windows-x86\swank.fas ... *** - OPEN: Directory #P"C:\Users\...\documents\.emacs.d\~\temp\" does not exist

I set temporary-file-directory to an absolute path, such as ""c:/Users/.../AppData/Local/Temp/" slime loads OK.

I grepped slime's lisp files for temporary-file-directory, but did not see it. I tested this with clisp -norc option.

Is this a bug - since on Windows Emacs accepts `~' for the home directory?

Thanks,

Mirko