Installing 2.8 automatically – zip error

I am trying to upgrade from 2.7.1 using the automatic option. When I run it I get the following error

Downloading update from http://ww.wp.xz.cn/wordpress-2.8.zip

Unpacking the core update

Incompatible archive: PCLZIP_ERR_BAD_FORMAT (-10) : Unable to find End of Central Dir Record signature

Installation Failed

I have tried the following:

– I have tried to do this on an apple mac and 2 windows pcs – all with same error

– I have tried disabling all plug ins and it still fails.

Any idea what is causing this. I am aware 2.8 seems a little buggy – but have not seen a reference to this problem