Hi Vapvarun, thanks for your response. However, it’s not just an auto installer glitch. I don’t think you know “free.fr” host. This host DOES requires the use of “index.php” in the permalinks structure, you just get 404 errors otherwise.
This a restriction imposed by this host provider. “Free.fr” is free but it imposes several restrictions in exchange. For example, out-going traffic, auto-updates, newsletters, private sites, and any rewrite rule in the “.htaccess” are all forbidden.
That’s why I was looking for a way to make buddypress working with “index.php” in the permalink structure. In the end, I gave up but it’s a shame cause buddypress is really a great plugin. I’d still be very interested if someone by any chance knows what I need to modify in buddypress to make it work for my particular case.