No, there is no option to set background image. Please go to http://forums.adobe.com/community/formscentral and click on Submit Feature Request at the top right of the page to submit a new feature idea. We use feature request list to evaluate new features in later releases.
Hi. I tried but after submitting it I got this reply:
" it appears you're not allowed to view what you have requested. You might contact your administrator if you think this is a mistake."
Did my submission still go through?
There are some issues with the "Submit Feature Request" right now so it probably didn't go through. We are working on a fix.