Recently, an odd behavior has begun to appear in editing. When I play the video in Sequence Preview, the red cursor jumps back for 0.5 - 1 s and repeats video and audio. This does not occur in the very beginning of the video, but a bit later , and very often. It also takes a very long time for VideoPad to start and close. The video is quite long, 1.5 hours, format 768 x 576 PAL video. Originally it has been captured from a Sony digital camcorder in AVI. Then it has been deinterlaced and converted to MP4 by HD Video Convert Factory Pro. VideoPad version is 8.32. Operating system is Windows 10. I have a quite capable PC, Intel i7 CPU, 16 GB RAM and 240 GB SSD, so this should not be a problem.
Editing in this situation is very difficult, so I would be really thankful for help.