I finally got the blank install.php isuue too, but only after I copied the wordpress-folder from the webserver (Linux-thing with Apache2) to my local development-machine (OS X.3, Apache 1.33, PHP4.something and mysql 4.0.24...). This didn't work as expected, so I did a fresh install of WordPress (installed a native WordPress from the downloaded files). this didn't worked as expected, so I went on boldly and deleted/recreated the MySQL-Database with a different Name, corrected wp-config.php, and -- still nothing but a blank page.
I am sure that both PHP and MySQL are working and cooperating (WordPress did fine 1 hour ago, PHPmyadmin works perfectly), but WordPress seems to have an issue...
I checked the files for trailing blanks and also changed the permissions to 777 (so they're fully open now, just to make sure this wouldn't be an issue) to no avail.
Blank Screen all over the place, me clueless.