I'm working on the testplan plugin, and noticed that an extra image was showing up on the PDF page. After digging, I realized it was the image I used to get the testplan able to jump to the last click step; essentially, at the end of the plan, I've set an img tag in the velocity template defined as:

<img src='/images/icons/emoticons/check.gif' heigth=0 width=0 onLoad="checkAnchors();"/>

checkAnchors looks at the URL to figure out if the user clicked a step, and sets the location of the window to that step so its not scrolled to the top on a long plan. In web browsers, the image is invisible, but the PDFs that are generated have the image show up at the end of the plan.