[Orgmode] Refile error - Kill is not a (set of) trees

[Michael Gilbert]

Hi all --

I am a noob - drawn to the alien world of Emacs (from my familiar Mac  
environment) by OrgMode. I am uncertain enough that I don't rightly  
know if this is best described as an OrgMode error or an Emacs error.  
Most likely a human error, I guess.

I am using last night's Aquamacs build: GNU Emacs 23.0.94.1 (i386- 
apple-darwin9.7.0, NS apple-appkit-949.46)
 of 2009-06-23 on BRAEBURN.PSY.CMU.EDU - Aquamacs Distribution  
2.0dev. Org-mode 6.21b.

In OrgMode, I am trying to learn to refile tasks. I use C-c C-w on a  
TODO item in a notes file. It goes through the process of allowing me  
to select the destination for the item. But then it throws an error -  
"Kill is not a (set of) trees" etc - every time. Doesn't kill the TODO  
and obviously doesn't yank it to the new location.

Any advice?

-- Michael