jumping screen

I have built a course that contains chapters and pages in each chapter, with mostly standard elements in Lectora. When I pupblish the course and uploaded it to our LMS, each time you go to a new chapter, the screen jumps. Literally - going to a new chapter either by navigation buttons, which are programmed to go to a particular chapter, or by completing one chapter and advancing to the next chapter. Is there a setting that can prevent this? I am not utilizing any transition of any kind to start a chapter or page within a chapter. These are just normal chapters and pages - no SWFs or any narration of any kind - they contain a few bullets and text. Please help me stop the jumping. By jumping, I mean the screen turns white, then the screen elements redraw. Sometimes the menu at the left stays on the screen and the content areas redraws - sometimes the entire screen goes white - then redraws. Once the redraw is complete, all the elements that should be on the screen are there - nothing is missing. Sometimes I don't get the jump from page to page within a chapter, but when I go to another chapter, it jumps. HELP!