I just discovered an incompatibility between Net Gearman and PHP 5.2.9+.  json_decode was changed in 5.2.9 to return NULL on invalid JSON strings.  Previously, the bare string had been returned if it was not valid JSON.  This was nice in a way as you could pass a scalar string to json_decode and not worry about it.  But, in reality, it would make debugging a nightmare for JSON.

I have updated my github fork and requested a pull into the main branch.  Once that is done a new PEAR release can be done.