What version of Videopad is being used? What format and resolution are the source files? What is the export format and resolution?
To iron this out please share the project and someone will check it out for you. It's not difficult.
Here's how... http://nch.invisionzone.com/topic/23659-tips-for-getting-help-on-this-forum/
If it contains sensitive material you can link it in a personal message (PM) to me, via the envelope above. Be sure to FILE|SAVE PORTABLE PROJECT AS, not simply SAVE PROJECT, and don't forget to share it.