Ok, it is not a limitation then. I'm not sure how I got there. It showed up while I was adding clips to the timeline. I created a new sequence just now and did not get the same result. For some reason the duration of my first sequence was not updated although I added clips at the end. I'll submit a support ticket if I manage to reproduce it.
I have created a sequence that is 38 minutes and 46 seconds long, but for some reason there is a darker section covering the sequence at around 0:38:10. When I tried to export it to a file, the movie ends at 0:38:10. Is there some kind of limit on how long sequences VideoPad can produce and export? And why would the limit then be 38 minutes and 10 seconds. I have not been able to find any information about any limit nor any setting to change this.