We have decided that TangoCMS 2.0, as well as the up-coming releases, will no longer support the PHP 5.1 series, due to many PDO bugs. The new PHP requirement will now be >= 5.2.

PDO (a PHP extension used within TangoCMS which provides the backbone for all the SQL goodness) within the 5.1 series of PHP appears to be quite buggy. This has meant that installing TangoCMS on the 5.1 series is impossible, as PDO will segfault and therefore causing an Internal Server Error.

As much as we'd like to support TangoCMS on as many PHP versions and environments as possible, we have to draw the line at some point. We apologize if this has caused any issues.