cygwin rvm and jruby

Hi,

I try to get a ruby on rails environment in cygwin running.
We use jruby(1.5.3), rvm, rails3 and several gems.

I installed rvm in cygwin and installed the desired jruby version via
rvm.
It worked. But when I now install gems they are not installed in the
appropriated folder. And a `gem list` shows me no local gems?!

Here some output:

snip

TPorschb@vporschberg ~/cobra-we
$ which ruby
/home/TPorschb/.rvm/rubies/jruby-1.5.3/bin/ruby

TPorschb@vporschberg ~/cobra-we
$ which gem
/home/TPorschb/.rvm/rubies/jruby-1.5.3/bin/gem

TPorschb@vporschberg ~/cobra-we
$ gem install bundler
JRuby limited openssl loaded. http://jruby.org/openssl
gem install jruby-openssl for full support.
Successfully installed bundler-1.0.7
1 gem installed

TPorschb@vporschberg ~/cobra-we
$ gem install haml
JRuby limited openssl loaded. http://jruby.org/openssl
gem install jruby-openssl for full support.
Successfully installed haml-3.0.24
1 gem installed

TPorschb@vporschberg ~/cobra-we
$ gem list

*** LOCAL GEMS ***

snip

The installed gems are only in the cache directory not in
.rvm/gems/jruby-1.5.3@rails3/gems

.rvm/gems/jruby-1.5.3@rails3/ keeps empty.

snip

TPorschb@vporschberg ~/.gem/jruby/1.8/cache
$ ls
bouncy-castle-java-1.5.0145.2.gem haml-3.0.24.gem
rake-0.8.7.gem
bundler-1.0.7.gem jruby-openssl-0.7.2.gem

snip

Any ideas?

Best regards
Thomas