[r-a-y]

Omit steps 38-41 in the tutorial above.

Your issue is really a WPMU<->bbPress integration and has nothing to do with BuddyPress.

It is definitely doable to integrate.

Last time I did it, I used WPMU 2.8.6 (i believe) and latest bbPress (1.0.2).

Might I suggest heading over to the bbPress forums?

https://bbpress.org/forums