final cut 7 - how to stop video from moving around in viewer?

Hi Guys

Any suggestions would be really appreciated.

In FCP7 the diagonal crosshair 'X' (I don't want to see this X) has appeared in my viewer over the video clip I wish to drag onto my timeline.

However, after setting my in and out points as normal, when I try to drag it down, the video moves in the viewer (revealing black space).

My question is, how can I somehow 'reset' the video in the viewer window back to its locked, original position, so I can drag it down onto my timeline as I used to?