Rubyinstaller users - Jun 2006 - gem install failure: Zlib::buffer

Hi,
I am getting a Zlib buffer (Zlib::BUFError) error when trying to
install rspec on a freshly installed Ruby in C:\Ruby.

ruby -e "require ''zlib''; p Zlib::ZLIB_VERSION"
returns 1.2.3
os: windows2000
ruby:184-17
gem: 0.8.11

I am new to ruby - there was also a support request logged by another
user. on 6 june ''06

Your advice will be much appreciated.

TIA