Vista - Gadgets move unexpectedly

I have a few gadgets on my desktop. The gadgets are not docked to the
sidebar, and the sidebar itself is not visible (by choice). I keep the
gadgets down the right hand side of the screen.

There are two users of the PC. When switching to the second user, doing some
work, then logging off that second user and logging back to the first user
(still logged on), I find the gadgets have moved about a 3rd of the way in
from the right hand side of the screen. I don't understand why this happens
or if there is a way to prevent it.

The second user has exactly the same desktop resolution and colour depth,
and their gadgets always appear where they were last left.

Does anyone have a similar situation?
Thanks
Mike