[support] Very disappointed, frustrated and concerned Drupal 7 problem

[Roger]

For days now I've been trying to overcome a Drupal 7 problem that I 
cannot explain.
Over the past year or two I have followed the same method for creating a 
copy of our live site to my Fedora 16 pc but as of 4 weeks ago, problems.

The Process:
-Copy of our live site database as a .sql file made by mysqldump 
thatdatabase > this file.sql. It has always for me provided a perfect 
copy of the database.
-Zip the whole web  site using cPanel.
-Download both to my Fedora 16 installation.
-Unzip the drupal system to /var/www/html/
-mysql -uuser -ppassword  create database (thatdatabase) same name user 
and password as the original.
-mysql -uuser -ppassword  thatdatabase < thisfile.sql
-Change settings.php a+w then remove the 15 lines in 
/sites/default/settings.php which access the database.
-Start the installation and enter the database name username and password.
Drupal copy fires up perfectly every time.
    ---- But ------
<structure><Content Types><Add content> gives WSOD, defaults to the 
stark theme with no options.
Views, Add Taxonomy, Add content, Rules, Permissions, Appearance, 
configurations, and others all work,

I have done the following: cleared caches,  drush cc all,  in myslq 
TRUNCATE cache and TRUNCATEd other cache files as per torials on google.
I have googled and found several others have the same problem but no one 
offers working solution.

http://localhost/mysite/admin/structure/types/add produces error:


    You are here

Home <http://localhost/eal719/> » Administration 
<http://localhost/eal719/admin> » Structure 
<http://localhost/eal719/admin/structure> » Content types 
<http://localhost/eal719/admin/structure/types>


  Content types

Add to /Default/ shortcuts 
<http://localhost/eal719/admin/config/user-interface/shortcut/shortcut-set-1/add-link-inline?link=admin/structure/types/add&name=Content%20types&destination=admin/structure/types/add&token=XF6dWGDfxNixfKkMhZMM-H4gWZ8lWudr7QvnKv8XnTs>

Individual content types can have different fields, behaviors, and 
permissions assigned to them.

Does anyone know what causes such a problem, what I should look out for 
to prevent future problems and best of all how to kill the problem once 
and for all.

Help greatly appreciated
Thanks in advance
Roger