WordPress Quick Cache Plugin
There is a new version of the WordPress Quick Cache plugin available.
Higher Minimum Requirements
This new version requires PHP 5.3+ This is a higher requirement than WordPress itself, which requires a minimum of PHP 5.2.4 (http://wordpress.org/about/requirements/).
Sometimes Newer is Not Better
If you are running on a server with sub PHP 5.3, you can manually install an old version of Quick Cache available at http://downloads.wordpress.org/plugin/quick-cache.111203.zip