BuddyPress.org

@helverk – I think the crucial difference between your site and Christina’s, is that you are experiencing your problems trying to set up a local test server.

Does your site function correctly without BuddyPress installed? Including using custom permalinks (e.g. /%category%/%postname%/). When you switch to custom permalinks without BuddyPress what url’s do you see? Do they still have index.php in them (it shouldn’t be there)?

If they do, the problem is probably something in your basic server / WordPress setup, rather than a BuddyPress problem