Making image overlay working on speciffic taxonomy terms....

Right!

What I want to do is to add an overlay (or watermark) that only applies to certain taxonomy vocabulary. So for instance I would have a "house" content item belonging to the taxonomy vocabulary "For sale!". Now, when the house gets sold the user switches the taxonomy vocabulary to "sold!". I then want drupal to apply an transparent png (or gif) to the image I uploaded into the imagefield (I'm using CCK) onto both the teaser version and full version of the cck node. I had a bit of a dabble with the "image" , "image gallery" and "image watermark" module, but it seems (I might be wrong here...) that it only works the first time you create a new note, not when you update, besides I would like to use CCK for constructing my content types. Anybody got some input on this?