I guess you were correct.
Somehow write permissions to the root of your web directory are needed … Strange, but thanks for the help !
The problem is that I don’t own the Apache configuration. It’s the one of my hoster.
I have the exact same problem. I did install wordpress 2.2 successfully, and the blog was working fine.
At some point I edited the wp-config.php file to switch to french langugae, and that is when the Internal Error started happening.
Blog is here : toulouse.trafic.free.fr/blog/
Maybe some strange character in the file got truncated wjen editing, thus causing the problen ?
Strange thing is that the admin interface seems to be working well.