Because i am a glutton for punishment i have ploughed on trying to get to the bottom of why my fresh stock install was failing (see earlier post) and have spotted an odd logged error in my root directory.
Code
[20-Jan-2015 19:50:03 UTC] PHP Notice:  Undefined variable: hr in /home/hcmaces/public_html/forum/includes/config.inc.php on line 7

Looking through my config.inc.php (that has been generated by the install script) i found that the only occurrence of the string "hr" is as part of a random generated password. The "hr" is preceded by a $. So i'm assuming that php is trying to interpret the last 3 characters of my DB password "$hr" as a variable reference...

A quick change of the db password to remove the $ later, and voila the install script runs to completion...

So i shall now continue with my investigations into my original issue...

This is what i do