What would cause the inability to rearrange slides in the Filmstrip view?

I have a Captivate 9 file with slides that I inserted and added text and pictures to along with software simulation (Demo) slides. I can add additional blank slides and enter text, etc. on them but when I try to move ANY of these slides to new positions so they are in the correct order, I am unable to do so. I drag and drop, but the slide always reverts back to where it was. I captured all of my simulations first and now want to go back and add some informational slides in between but I cannot get these to move to the location I need them to be in. I am on Captivate 9.0.2.437. I have cleared the cache in Preferences, restarted Captivate, copied and pasted slides into a new file, etc. but nothing has worked. For example, I select the first slide, Insert a new blank slide...enter text and graphics but am unable to move that slide before the first one. I have not found any resolution to this in previous posts so I am hoping someone can help. Thanks.