You need to use escaped html to add images to your bubbles in the timeline project- The CDATA tag doesn't seem to work -here is a little tool that will write them for you:
<a href="http://www.reconn.us/component/option,com_wrapper/Itemid,62/">http://www.reconn.us/component/option,com_wrapper/Itemid,62/</href>
so you put <img src=?image.jpg?/> in the box and it will write the escaped html for you- just paste it into the description either before or after your description text (with a space of course) and it should add your pic as long as it is in the root folder of your webserver.