Word automatically snaps to bottomof page.

[Rory]

Hello,
While using Word 2003, and this seems to be sporadic, the page will
automatically snap to the bottom. Attempting to scroll back up with the
scroll bar results in the same behavior after releasing the scroll bar.
Also, cannot scroll to the top with the mouse wheel. Shutting down and
relaunching Word seems to resolve the issue temporarily.
Any ideas?
Thanks!