I've just installed Classipress and posted a new ad to test.
I noticed i have a bug within the display of category listings.
I attache to this post 2 images to help understanding that bug: one is in frend and from my site, and the second is from your online demo.
In fact i have a big white space between the ad thumbnail and the ad metas !
Hope that someone will be able to provide some help.
Regards.