Hello Alex/Twitter, I am not seeing any errors on my side, but several times in the past couple days...new follower relationships aren't being created when they are supposed to be.
A particular case is "snaptweet" and "ssethi". SnapTweet supposedly created a 2-way relationship there and Twitter doesn't think so. Did you happen to change the /friendships/create/user.xml method recently? Or could this possibly related to cache problems this week? I did find one user (Reemski) who was able to sign up recently and the follows worked, but she is not the norm. I am now going to go in and attempt to manually do the follows. Hopefully they will "take". Thanks, -damon