I am having the exact same problem when trying to run the install script on my hosting account at Buzzsawhosting(http://www.buzzsawhosting.com). They keep telling me it's the script's problem.
Doesn't look like anyone is answering this problem here. Does anyone know why this happens?
You might want to try dropping a test html file in your root folder (where the index.php is for ezpublish) and see if you can pull that up in a browser. Do you have any other sites running successfully on the server? Just trying to narrow it down to an eZ problem or a server config problem.