Image Resizing and Shifting Excel 2007

Hi, if anyone can offer me some help i'd really appreciate it, basically
whenever I import images into an Excel document formatted as a presentation
(which I have been doing for quite a while using previous versions of Excel)
everytime I save and reopen the file the images have moved around the page
and changed size, its only when i either resize and reposition or (sometimes
this works) zoom in and out again that they return to their original size and
position.
Im not doing anything different to the way I have gone about it for the last
few years so I assume the fault lies with Excel 2007.
PLEASE HELP!!! :)
.