I'm not sure how long this has been doing this, but every text message I receive lately that was sent from LJ text messaging has had the From: listed as firstname.lastname@example.org regardless of the actual sender. I used to get the sender's lj email@example.com and I was able to tell whom it was from.
My Service Provider is Verizon Wireless and I have my Security Level set to Registered Users.
I'm not sure if this is a bug or if it was intentionally changed. I would like to have the lj username appear again if it is at all possible.
I'm also more than willing to help out in any testing that you may need.
I apologize if this was already caught and corrected in the next version.