Permission problem under WinXP

Hi All,

I generated a Ruby on Rails app, which among other things, had to
import content from a bunch of CSV files from time to time. When I
generated the app, I had a typo: I used cvs instead of csv. When I
started coding, I used csv. It got to be a mess. Being pigheaded I
decided to write a ruby script to transform all file-names and file
content to conform to csv.

The transformation script is posted at http://www.pastie.org/323198.
I've tested the code thoroughly, so I think its really a Windows
problem: it's keeping a lock on the file(s) I'm using despite the
fact that I issued Ruby close commands.

I wonder if anyone has a quick fix for this problem. If not, I'll
walk the extra mile and write my filename changes to disk and write a
stand-alone app to apply those changes. But if there's a slick way to
solves this, I'd like to learn it.

Thanks in Advance,
Richard