Just to let you know that the Piwik extension (planned for 1.4.4) works fine on my shared host.

Piwik version 1.8.2

Zenphoto version 1.4.3 [10393] (Official build)
PHP version: 5.3.15
Graphics support: PHP GD library bundled (2.0.34 compatible)
MySql version: 5.5.9

Thaks for the update.