It was originally "FROM bere_lastreads", but I changed it to [prefix] to avoid confusion. This isn't an issue, it's just my database adds a prefix before the table name.
But I fixed it, I think. The issue was, the user somehow ended up without a userid. Possibly mySQL failed during registration. I fixed it by getting them to sign up again. I don't think it was your hack causing the problem. Thanks, though.