UTF8 name not carried into the page cache filename

I am using ruby 1.8.7 and rail 3 beta3 on Windows XP.

Page caching works okay and the content of the cache is UTF8 as
expected. However, the filename which came from the UTF8 URL is not
okay.

Apache can not find the file because it is not filed as a UTF8
filename but something else.

I do not know whether this is a Rails 3 bug or something I did wrong.
Can anybody help?

I have concluded that the problem is not Rails or Rails3. I have come
to believe it is a Ruby problem. I have sent the comments below to a
ruby forum.