wordpress install wipes website from other folder

[stevema]

Bluehost have not been able to help me. Maybe someone here can???
I built a wordpress site domain A in folder A, I then transferred it into folder B and changed its domain name to B, freeing up the domain A.
After deleting the content of A I did a new wordpress install in folder A and immediately folder B collapsed. My two websites B and C just said database error. No restore worked until bluehost did a full cpanel month install (By this time I had lost the data from the weekly one because over a week had passed.)
At the moment I have asked them to restore a download of a weekly restore but most support tickets take a day or two to get a response so the whole thing is taking rather long.
DOes anyone have an idea why this happened. I am probably going to have to rebuild my website and I do not want the same thing to happen again when I re-install wordpress in folder A!!!!!!!
my website is http://www.stasaphchiro.co.uk

[johnmcrin]

When I POST a form to the same .php file a file-scope variable is null when it shouldn't be.

includefile.php:
<?php
$foo = " ";
?>

doIt.php:

<?php
echo $foo;
echo <<<_END

[code]....

The first time it loads, index.php causes $foo to echo and it says "Set now." But when I press the submit button on the form -- $foo is empty. Why does re-entry into doIt.php kill the value of $foo? the require_once changed nothing -- still same problem. My guess is that the form POST and the resulting re-entry into the same .php file sets up a new call frame on the stack with everything set to nothing.

Regards
John