I've been using VideoPad 10.24 for some time now after using the free version for a few years before that. Each time I added new videos or photos to the sequence, the blue bar always gradually crept along and turned purple, and then I'd be able to watch the sequence without the "Building Preview" box flashing and periodically freezing. Recently, the blue bar has only been turning purple for a short duration, and not right up to the end of the video. Why is this happening, and does it effect the video on export?