Homepage Slideshow: Increase # of slides

How do you increase the # of slides on the homepage slideshow? I am relatively new to WordPress so could use any assistance. Our website is http://www.tabarealty.com. The # of posts I have featured is 6 but there are only 5 slides. The older slide that is no longer showing was showing up fine until I added new slides. I think there is a limit to the # of slides I can have, but I don’t know where to edit that information. Thanks!