Yeah, I can't slide the tab either way. That was an FC/M feature I believe (and possibly on some of the later FCW's).
With the back off the camera, it acts the same way. I can only wind using the multi exposure button. I fire, push the button in and then wind to advance. The only way to change the status indicator on the back is manually winding on the back itself it but as soon as I fire again, it's back to the red color.
No worries dude! You dedicating all of these posts to helping me out is big enough. I'll have to try another new battery out, I'm just hoping that's the problem.