I found some bug in postgrey connection.
I Don't now exactly were, but when I chage '$connect_string' in line 79: $this->db_connect_id = ...
to my 'host=localhost port=5433 dbname=IG-phpBB user=IG-phpBB password=y6FVNN9ec2b6MaKy'
I think problem near port or host when the string are creating. Because with port = 5432 and host=172.17.1.16 (typed in config) works great
I hope you fix it