When trying to install Piwik 2.8.3 I kept getting “PHP version 5.3.3 PHP version > 5.3.3 : Error: PHP version > 5.3.3 required” even though my server was running PHP 5.3.3.
To fix this I modified piwik/core/testMinimumPhpVersion.php
Change line 19 from
$piwik_minimumPHPVersion = '5.3.3';
$piwik_minimumPHPVersion = '5.3.2';
Upload this file to your webserver and overwrite the existing file then refresh the system check page, it should get past that stage now.