Zlib::BufError on gem update

Hi,

I’ve just run the usual gem update --include-dependencies in order to
update to 1.0 and I get the following error:

Upgrading installed gems…
Attempting remote upgrade of actionwebservice
Attempting remote installation of ‘actionwebservice’
ERROR: While executing gem … (Zlib::BufError)
buffer error

Subsequent attempts gives me the same error. Can anyone help? I’m on
WinXP.

Many thanks

Charles