BuddyPress Avatars: missing directory and unable to upload

I'm having an issue with BuddyPress and it's profile avatars.

First of all activating the plugin does not create the 'avatars' directory in 'uploads'. I've checked permissions and they seem to be okay. However, even creating the directory manually does nothing to fix the problems I describe next.

Secondly, even with the 'Allow members to upload profile pictures' feature enabled, there's no UI for changing the profile picture from users profiles.

And thirdly, when I view profiles from within the WP admin area, there's a link to 'Delete Profile Photo', but clicking that link returns an error message stating that the app could not delete the file (which makes sense, as it doesn't exist).

I'm at my wits end, and could really use some help here.