The Bug Genie 3 requires PCRE librairies 8.0 or later. You have version 7.8 2008-09-05. Update your system to the latest release from your usual sources.
I think you have to manually build PHP against newest PCRE library using --with-pcre-regex=DIR
option. To do so, you need to obtain the PHP sources and PCRE sources, as well as sources of all other libraries you might need.
This page http://php.net/manual/en/pcre.installation.php summarizes versions of PCRE bundled with PHP.
The much easier option would be updating PHP using package manager of your OS (perhaps by enabling unstable repositories), but this depends on your OS.