Yea, I had this problem with my mazda as my wife didn't have a remote and was always setting it off. You need to put your manual key in and turn the car off and on 3 times to reset it. Might be different for your ford. Then I read that there was an alarm "reset" button in the fusebox. So I found it, and taped it down... no more alarm. So I ripped out the stupid button and soldered the leads together so I'd never have to bother with it again. You want to steel my car? I'll give you my friggen address.
Was there a happy dance to do too? I know the need for security, but that borders on the ridiculous. All that is missing is the ctrl-alt-delete key.