I have been around here for a little while, and seemingly made a random post when my computer had logged me out using the same email address. It made me reregister an account, and now I can't access any of my old information on posts, replies, etc.
I had this problem, too. So now I have an account that I use when in on my desktop, and o e I use on my phone. I can't do anything because I'm not registered, but can't register because my email address in already in use. It's all very frustrating.