Hmmm … I have other buddypress and wordpress mu plug ins, not much but few.
When I downgrade to Version 1.2.3 of buddypress things work okay.
But using the 220.127.116.11 version causes problem. Did they introduce some bug somewhere ? ( Maddening for me!)
Have you got a working site with BOTH buddypress 18.104.22.168 and WordPress -mu-2.9.2 ? Any web link please ?