Summary command "o" and "O" results in "wrong type argument listp,

[Marc Croteau <mdcroteau@gmail.com>]

[This mail was also posted to gmane.mail.wanderlust.general.]

Hello folks

Hope someone can help.
I'm wanting to refile messages.
When I issue the 'o' or "O" command in the summary area, I get a message:
Wrong type argument: listp, 71
I don't know what to make of this.
Initially, I though that because I didn't have wl-refile-rule-alist 
initialized, that this was causing some problems.
So..I did the following
(setq wl-refile-rule-alist 
   '(("To" ("pan-users" . "_Lists"))))

_Lists is a maildir folder.

Any help would be appreciated.
Regards,
Marc