Strange – I use the same versions and my online list works just fine.
Unfortunately, Detective’s solution doesn’t work with the latest versions. I’m experiencing the same issues (integrated scenario):
User registers on bbpress and logs in there
User can acces the WP Site Admin section, but it says: Welcome, . (a space instead of the user name)
User comments are registered as ‘Anonymous’
I noticed the only way to fix this is to go to WP user management panel, editing and saving the user.
So the user has to be actively (and manually ) updated to have his name listed under his comments.
I haven’t found any way to avoid this, but if anyone can I’d be much abliged!