I've installed WP a zillion times but this is the first time I've had this issue, so I'm thinking it must have something to do with Magento.
Here's the scoop. I'm setting up a WP blog for a client whose entire site is a shopping cart powered by Magento. I've uploaded a fresh install of WP (at /blog - Magento runs off the root) and configured wp-config.php correctly, and then I go to the install page.
I enter the blog name and my email, click 'Install WordPress', and immediately get sent to http://www.mydomain.com/blog/wp-admin/install.php?step=2 and a 404 error page.
Magento is not something I'm all too familiar with but the .htaccess file it uses is a monster, and I wonder if it's doing something to the permalinks that's confusing WP. (Incidentally, it's MySQL 5, and running off a new database.)
I've Googled this and found loads of folk with this problem (although not Magento-specific), but not a single solution.
It's kind of a big deal, so any help would be appreciated.
Note: I'm not sure about sharing the link to my 'installation', as obviously it's not currently configured and I'm a bit nervous about somebody pulling a fast one. I can do this privately through a trusted authority on these forums if necessary. :)