Last night we upgraded PHP in the Grid from 5.3.15 to 5.3.16. This new release patches over 20 bugs and security vulnerabilities existing in 5.3.15.
PHP 5.3.16 is active only on the Grid's Debian 6 environment. To change your hosting environment, login to OnSite. This upgrade should not cause any application issues. For a full list of changes between 5.3.15 and 5.3.16, visit php.net.
As always, let us know if you have any issues resulting from this upgrade.