Hi - Well the good news is at last it is working. So what did I do. I commented out the line in the php.ini which says - extension=pgsql.so - restarted apache - checked the pg-hba.conf (just to make sure) and restarted postgres, again just to be sure, and now things are playing properly. The question now is why it wasn't doing this to start with???.
The originall quest was have php / postgres / apache all talking to each other, as I have under a windows OS. Browsing the forum I came accross a similar post which I thought maybe worth a try. As follows.
mkdir - /etc/e-smith/templates-custom/etc/php.ini
add file 70PgsqlExtension
add one line extension=pgsql.so
expand the php.ini file with
sbin/e-smith/expand-template /etc/php.ini
Before this nothing happened with postgres, after I expanded the template the error appeared. There also seems to be a generall acceptance that - extension=pgsql.so - is a requirement for all this to work. Again this makes sence to me assuming pgsql.so is the equivelent to windows php_ggsql.dll (maybe !).
Searching google with the error confirmed it was in fact a PHP error because there was two files with the line - extension=pgsql.so. removing this from php.ini has things working. So has expanding the templates-custom somehow awakened the redhat file.!!!