Thanks for getting back to me.
This was one of my very early considerations before I noticed the space issue.
However, all the images on that page are hosted on another domain.
<img src="../image_cache/site/www.seemysale.co.uk/public/seemylocalshop/crop/P5211465_w75_h60/P5211465_11091117.jpg" alt="" width="75" height="60" border="0"/>
But Image resizer appears to work for them?
Its just the odd few, with spaces, that don't seem to work.