From a story:
http://www.columbian.com/business/APSto ... 127468.cfm
A number of images are blocked by the filter /banners/*.gif$~background
However, there are a number of others that are not, because they are .jpg instead.
Might be worth adding a .jpg version of the above rule too (unless there's a reason it's currently gif-only).
EDIT - there were a couple of others I missed earlier that are easy to block too:
http://www.columbianonline.com/_images/ ... ogo258.jpg
etc
Block something like */adLogo* ?