If images load, display normal, then slowly turn white, it's because the Flash Player doesn't think it has security clearance to manipulate the images requested/loaded by SlideShowPro. There are two ways to avoid this.
1) Add/edit a crossdomain.xml file to the root of the site where content is being loaded from so that it includes the domain where your SWF is embedded. This is covered in detail in the Can't load XML data from a different domain document.
2) If #1 above isn't technically possible, you will need to change the component's OPTIONS/Smoothing parameter to "Off". This should allow the image to load successfully and not turn white.