That account is created when the .NET Framework is installed. It's a special use account, so don't worry about it.
You can either disable it, to get the auto login to work, or you can download TweakUI and use it to set which account to automatically log into at boot. The latter being the better option.
Usually when turning the computer on it just goes into the only account. But now it DOES bring up the screen but only shows the one account. I went to User Accounts in the control pannel and there is this strange account. This is its info:
ASP.NET Machine A...
I really have no idea what it is or where it came from, but could it be the reason for the logon screen coming up?