[Plugin: Global Plugin Update Notice] cannot upgrade to latest version

An error has occured
A problem has occured while unpacking your plugin package!

that’s always the error message returned when i try to install the newest version of this plugin. i’m using WP 2.5.1. i already tried unpacking it then uploading to server via ftp, its there in my plugins. but it will not be upgraded in wp admin..wats up wid dat!

http://ww.wp.xz.cn/extend/plugins/global-plugin-update-notice/