It's hard to describe, please just follow these steps.
1. Open a new Writer document
2. Window → New Window (to open another window of the same document)
3. Zoom in the page in the first window to the maximum (Ctrl + mouse wheel up)
4. Zoom out the page in the second window to the minumum (Ctrl + mouse wheel down)
The page in first window moves, but should not.
And the lousy description:
When you have multiple windows open of the same document, when you change zoom level in one window, in some cases page position in other windows moves.
I see nothing wrong on LO 18.104.22.168 (Win7 Home Premium 32bit)
Could you attach sample document & screenshot?
After 3rd point can you make sure that you see fully zoomed in top left corner of the page in the first window?
If that doesn't help you reproduce it, I will learn how to record a screencast. FWIW, it happended both on Mac OSX and Ubuntu Linux, so it very likely will happen on Windows as well.
On pc Debian x86-64 with master sources updated today, I reproduced this.
Caolán: the bug is on Writer but I wonder if it could be vcl related, any idea?
Same happens back in OpenOffice.org 3.2.0 as well, so apparently not new. Seems to be only writer where it happens e.g. not in calc as far as I can see
*** This bug has been marked as a duplicate of bug 43253 ***