You can certainly do this. However, it does make slide editing a bit difficult, nonetheless, it can be done. Here's how to do it:

  • create a new slide using the Create a new slide using the Slide Editor option
  • click the HTML Source Editor (a button on the tool bar that says HTML on it) button to open the WYSIWYG editor
  • paste in following source code:  <div style="background-image: url(http://www.seavn.com/wp-content/uploads/2011/04/Beautiful-Waves-17.jpg); height: 480px;">here is my text</div>
  • replace the image URL (http://www.seavn.com/wp-content/uploads/2011/04/Beautiful-Waves-17.jpg) with the location of your preferred image
  • replace the "here is my text" with your own text
You can then save your work and go back to the regular slide view to revise your text and add in hyperlinks if desired.

Note: any time you need to add a line break when moving the text on the screen be sure to hold down the shift key before pressing enter