Needing some help reguarding twitter?

[rossy hearse]

Okay, I need something cleared up on twitter. One day I'm following this twitter user and he's following me back, and the next it shows up that I'm not following him nor is he following me. I look him up (both of his accounts) and it says "this user does not exist". And then a couple of days later I go to my direct messages, and see that he changed his profile picture (I forgot to delete our direct messages). Then I try to follow him again and I get the same message I did before, "this user does not exist." Can anybody help?? Thanks