Hi 4Shades, I really appreciate your efforts to help me!

Now a couple of questions.
I have used the split version fon one of my BD and the full for the other.
Should I insert the same data of my Ardennes (fer example) inside all other connection section, even if I don't use them? I explain it more clearly : in Administration php script I should fill all rows with the same data as for the Ardennes sector (localhost, hostname, password and DBname) even if the other ones are unused?
What should I do to set my server up for heavy duty? You mean I should set my machine as a "only MySQL" machine (dedicated server) for full memory usage? Now it is set as web server application (sorry if I'm not completely clear).
I maybe will try to reinstall the MP and its scripts to make sure I reset the permissions, because my PHP should work correctly according to the phpinfo test. Also I'm able to run the Admin page correctly, so the problem should not be the web server or php.
Thanks again for your patience!