Working with Characters and Backgrounds in Captivate 6

Hello,

I'm trying to insert art from E-Learning Art as a background for the characters in Captivate 6, and I'm having two problems:  

1) I added one picture (.jpg photograph) and it shows up on every slide.   It is not in the master slides, and I do not want it on every slide.  How do I remove the picture from the slides where I want to put another background? 

2) When I preview my slides, the characters have an obvious white line around them and in some cases a glow.  Any suggestions for correcting this? 

Thanks in advance for your help!