Strange indeed. Have you checked the Windows microphone settings? Right-click, then click PROPERTIES.

Does the same thing occur when using Windows Voice Recorder to create a file?
Try a reinstall of Videopad. Here's the latest. For licensed users upgrades are free for up to six months from purchase date. After that, VP will continue to fully function but a fee will be required in order to register the newest. Retain your old install file and registration info.