I'm knee-deep in the middle of a project, so reproducing the problem will have to wait.
What I can tell you is that the product seems to be buggy when you embed it directly into PHP/MySQL code. I had higlighted an IMG SRC element within a nested loop and then applied Image Resizer from the CS4 Webassist > Image Resizer menu navigation when it happened. Subsequently I found another thread on this forum where it was recommended that the user construct the resizing code outside of the PHP and then paste it into the desired code or routine. That ended up being my workaround, for now. The tech who addressed that somewhat similar scenario implied that it was a bug that was to be rectified in the next release. Having said that, I apologize for being so harsh. It really is a nice product overall.