I uninstalled the Worpdress 2.9.1 and wanted to install WP-MU instead. I deleted all files (hidden and not) corresponding to WP-2.9.1. I created a new database deleting the old one, followed the simple isntructions. Delted the .htaccess file and also set the permissions to all. I haven't messed up the files or the directories but still when I press 'Submit' on the first Installation page, I get a blank white screen.
I am using Linux Shared Hosting.